Age Owner Branch data TLA Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * slot.c
4 : : * Replication slot management.
5 : : *
6 : : *
7 : : * Copyright (c) 2012-2026, PostgreSQL Global Development Group
8 : : *
9 : : *
10 : : * IDENTIFICATION
11 : : * src/backend/replication/slot.c
12 : : *
13 : : * NOTES
14 : : *
15 : : * Replication slots are used to keep state about replication streams
16 : : * originating from this cluster. Their primary purpose is to prevent the
17 : : * premature removal of WAL or of old tuple versions in a manner that would
18 : : * interfere with replication; they are also useful for monitoring purposes.
19 : : * Slots need to be permanent (to allow restarts), crash-safe, and allocatable
20 : : * on standbys (to support cascading setups). The requirement that slots be
21 : : * usable on standbys precludes storing them in the system catalogs.
22 : : *
23 : : * Each replication slot gets its own directory inside the directory
24 : : * $PGDATA / PG_REPLSLOT_DIR. Inside that directory the state file will
25 : : * contain the slot's own data. Additional data can be stored alongside that
26 : : * file if required. While the server is running, the state data is also
27 : : * cached in memory for efficiency.
28 : : *
29 : : * ReplicationSlotAllocationLock must be taken in exclusive mode to allocate
30 : : * or free a slot. ReplicationSlotControlLock must be taken in shared mode
31 : : * to iterate over the slots, and in exclusive mode to change the in_use flag
32 : : * of a slot. The remaining data in each slot is protected by its mutex.
33 : : *
34 : : *-------------------------------------------------------------------------
35 : : */
36 : :
37 : : #include "postgres.h"
38 : :
39 : : #include <unistd.h>
40 : : #include <sys/stat.h>
41 : :
42 : : #include "access/transam.h"
43 : : #include "access/xlog_internal.h"
44 : : #include "access/xlogrecovery.h"
45 : : #include "common/file_utils.h"
46 : : #include "common/string.h"
47 : : #include "miscadmin.h"
48 : : #include "pgstat.h"
49 : : #include "postmaster/interrupt.h"
50 : : #include "replication/logicallauncher.h"
51 : : #include "replication/slotsync.h"
52 : : #include "replication/slot.h"
53 : : #include "replication/walsender_private.h"
54 : : #include "storage/fd.h"
55 : : #include "storage/ipc.h"
56 : : #include "storage/proc.h"
57 : : #include "storage/procarray.h"
58 : : #include "storage/subsystems.h"
59 : : #include "utils/builtins.h"
60 : : #include "utils/guc_hooks.h"
61 : : #include "utils/injection_point.h"
62 : : #include "utils/varlena.h"
63 : : #include "utils/wait_event.h"
64 : :
65 : : /*
66 : : * Replication slot on-disk data structure.
67 : : */
68 : : typedef struct ReplicationSlotOnDisk
69 : : {
70 : : /* first part of this struct needs to be version independent */
71 : :
72 : : /* data not covered by checksum */
73 : : uint32 magic;
74 : : pg_crc32c checksum;
75 : :
76 : : /* data covered by checksum */
77 : : uint32 version;
78 : : uint32 length;
79 : :
80 : : /*
81 : : * The actual data in the slot that follows can differ based on the above
82 : : * 'version'.
83 : : */
84 : :
85 : : ReplicationSlotPersistentData slotdata;
86 : : } ReplicationSlotOnDisk;
87 : :
88 : : /*
89 : : * Struct for the configuration of synchronized_standby_slots.
90 : : *
91 : : * Note: this must be a flat representation that can be held in a single chunk
92 : : * of guc_malloc'd memory, so that it can be stored as the "extra" data for the
93 : : * synchronized_standby_slots GUC.
94 : : */
95 : : typedef struct
96 : : {
97 : : /* Number of slot names in the slot_names[] */
98 : : int nslotnames;
99 : :
100 : : /*
101 : : * slot_names contains 'nslotnames' consecutive null-terminated C strings.
102 : : */
103 : : char slot_names[FLEXIBLE_ARRAY_MEMBER];
104 : : } SyncStandbySlotsConfigData;
105 : :
106 : : /*
107 : : * Lookup table for slot invalidation causes.
108 : : */
109 : : typedef struct SlotInvalidationCauseMap
110 : : {
111 : : ReplicationSlotInvalidationCause cause;
112 : : const char *cause_name;
113 : : } SlotInvalidationCauseMap;
114 : :
115 : : static const SlotInvalidationCauseMap SlotInvalidationCauses[] = {
116 : : {RS_INVAL_NONE, "none"},
117 : : {RS_INVAL_WAL_REMOVED, "wal_removed"},
118 : : {RS_INVAL_HORIZON, "rows_removed"},
119 : : {RS_INVAL_WAL_LEVEL, "wal_level_insufficient"},
120 : : {RS_INVAL_IDLE_TIMEOUT, "idle_timeout"},
121 : : };
122 : :
123 : : /*
124 : : * Ensure that the lookup table is up-to-date with the enums defined in
125 : : * ReplicationSlotInvalidationCause.
126 : : */
127 : : StaticAssertDecl(lengthof(SlotInvalidationCauses) == (RS_INVAL_MAX_CAUSES + 1),
128 : : "array length mismatch");
129 : :
130 : : /* size of version independent data */
131 : : #define ReplicationSlotOnDiskConstantSize \
132 : : offsetof(ReplicationSlotOnDisk, slotdata)
133 : : /* size of the part of the slot not covered by the checksum */
134 : : #define ReplicationSlotOnDiskNotChecksummedSize \
135 : : offsetof(ReplicationSlotOnDisk, version)
136 : : /* size of the part covered by the checksum */
137 : : #define ReplicationSlotOnDiskChecksummedSize \
138 : : sizeof(ReplicationSlotOnDisk) - ReplicationSlotOnDiskNotChecksummedSize
139 : : /* size of the slot data that is version dependent */
140 : : #define ReplicationSlotOnDiskV2Size \
141 : : sizeof(ReplicationSlotOnDisk) - ReplicationSlotOnDiskConstantSize
142 : :
143 : : #define SLOT_MAGIC 0x1051CA1 /* format identifier */
144 : : #define SLOT_VERSION 5 /* version for new files */
145 : :
146 : : /* Control array for replication slot management */
147 : : ReplicationSlotCtlData *ReplicationSlotCtl = NULL;
148 : :
149 : : static void ReplicationSlotsShmemRequest(void *arg);
150 : : static void ReplicationSlotsShmemInit(void *arg);
151 : :
152 : : const ShmemCallbacks ReplicationSlotsShmemCallbacks = {
153 : : .request_fn = ReplicationSlotsShmemRequest,
154 : : .init_fn = ReplicationSlotsShmemInit,
155 : : };
156 : :
157 : : /* My backend's replication slot in the shared memory array */
158 : : ReplicationSlot *MyReplicationSlot = NULL;
159 : :
160 : : /* GUC variables */
161 : : int max_replication_slots = 10; /* the maximum number of replication
162 : : * slots */
163 : : int max_repack_replication_slots = 5; /* the maximum number of slots
164 : : * for REPACK */
165 : :
166 : : /*
167 : : * Invalidate replication slots that have remained idle longer than this
168 : : * duration; '0' disables it.
169 : : */
170 : : int idle_replication_slot_timeout_secs = 0;
171 : :
172 : : /*
173 : : * This GUC lists streaming replication standby server slot names that
174 : : * logical WAL sender processes will wait for.
175 : : */
176 : : char *synchronized_standby_slots;
177 : :
178 : : /* This is the parsed and cached configuration for synchronized_standby_slots */
179 : : static SyncStandbySlotsConfigData *synchronized_standby_slots_config;
180 : :
181 : : /*
182 : : * Oldest LSN that has been confirmed to be flushed to the standbys
183 : : * corresponding to the physical slots specified in the synchronized_standby_slots GUC.
184 : : */
185 : : static XLogRecPtr ss_oldest_flush_lsn = InvalidXLogRecPtr;
186 : :
187 : : static void ReplicationSlotShmemExit(int code, Datum arg);
188 : : static bool IsSlotForConflictCheck(const char *name);
189 : : static void ReplicationSlotDropPtr(ReplicationSlot *slot);
190 : :
191 : : /* internal persistency functions */
192 : : static void RestoreSlotFromDisk(const char *name);
193 : : static void CreateSlotOnDisk(ReplicationSlot *slot);
194 : : static void SaveSlotToPath(ReplicationSlot *slot, const char *dir, int elevel);
195 : :
196 : : /*
197 : : * Register shared memory space needed for replication slots.
198 : : */
199 : : static void
29 heikki.linnakangas@i 200 :GNC 1244 : ReplicationSlotsShmemRequest(void *arg)
201 : : {
202 : : Size size;
203 : :
28 alvherre@kurilemu.de 204 [ - + ]: 1244 : if (max_replication_slots + max_repack_replication_slots == 0)
29 heikki.linnakangas@i 205 :UNC 0 : return;
206 : :
4477 rhaas@postgresql.org 207 :CBC 1244 : size = offsetof(ReplicationSlotCtlData, replication_slots);
208 : 1244 : size = add_size(size,
28 alvherre@kurilemu.de 209 :GNC 1244 : mul_size(max_replication_slots + max_repack_replication_slots,
210 : : sizeof(ReplicationSlot)));
29 heikki.linnakangas@i 211 : 1244 : ShmemRequestStruct(.name = "ReplicationSlot Ctl",
212 : : .size = size,
213 : : .ptr = (void **) &ReplicationSlotCtl,
214 : : );
215 : : }
216 : :
217 : : /*
218 : : * Initialize shared memory for replication slots.
219 : : */
220 : : static void
221 : 1241 : ReplicationSlotsShmemInit(void *arg)
222 : : {
28 alvherre@kurilemu.de 223 [ + + ]: 19654 : for (int i = 0; i < max_replication_slots + max_repack_replication_slots; i++)
224 : : {
29 heikki.linnakangas@i 225 : 18413 : ReplicationSlot *slot = &ReplicationSlotCtl->replication_slots[i];
226 : :
227 : : /* everything else is zeroed by the memset above */
228 : 18413 : slot->active_proc = INVALID_PROC_NUMBER;
229 : 18413 : SpinLockInit(&slot->mutex);
230 : 18413 : LWLockInitialize(&slot->io_in_progress_lock,
231 : : LWTRANCHE_REPLICATION_SLOT_IO);
232 : 18413 : ConditionVariableInit(&slot->active_cv);
233 : : }
4477 rhaas@postgresql.org 234 :GIC 1241 : }
235 : :
236 : : /*
237 : : * Register the callback for replication slot cleanup and releasing.
238 : : */
239 : : void
1541 andres@anarazel.de 240 :CBC 22950 : ReplicationSlotInitialize(void)
241 : : {
242 : 22950 : before_shmem_exit(ReplicationSlotShmemExit, 0);
243 : 22950 : }
244 : :
245 : : /*
246 : : * Release and cleanup replication slots.
247 : : */
248 : : static void
249 : 22950 : ReplicationSlotShmemExit(int code, Datum arg)
250 : : {
251 : : /* Make sure active replication slots are released */
252 [ + + ]: 22950 : if (MyReplicationSlot != NULL)
253 : 289 : ReplicationSlotRelease();
254 : :
255 : : /* Also cleanup all the temporary slots. */
740 akapila@postgresql.o 256 : 22950 : ReplicationSlotCleanup(false);
1541 andres@anarazel.de 257 : 22950 : }
258 : :
259 : : /*
260 : : * Check whether the passed slot name is valid and report errors at elevel.
261 : : *
262 : : * See comments for ReplicationSlotValidateNameInternal().
263 : : */
264 : : bool
195 fujii@postgresql.org 265 :GNC 863 : ReplicationSlotValidateName(const char *name, bool allow_reserved_name,
266 : : int elevel)
267 : : {
268 : : int err_code;
195 fujii@postgresql.org 269 :CBC 863 : char *err_msg = NULL;
270 : 863 : char *err_hint = NULL;
271 : :
195 fujii@postgresql.org 272 [ + + ]:GNC 863 : if (!ReplicationSlotValidateNameInternal(name, allow_reserved_name,
273 : : &err_code, &err_msg, &err_hint))
274 : : {
275 : : /*
276 : : * Use errmsg_internal() and errhint_internal() instead of errmsg()
277 : : * and errhint(), since the messages from
278 : : * ReplicationSlotValidateNameInternal() are already translated. This
279 : : * avoids double translation.
280 : : */
195 fujii@postgresql.org 281 [ + - + + ]:CBC 5 : ereport(elevel,
282 : : errcode(err_code),
283 : : errmsg_internal("%s", err_msg),
284 : : (err_hint != NULL) ? errhint_internal("%s", err_hint) : 0);
285 : :
195 fujii@postgresql.org 286 :UBC 0 : pfree(err_msg);
287 [ # # ]: 0 : if (err_hint != NULL)
288 : 0 : pfree(err_hint);
289 : 0 : return false;
290 : : }
291 : :
195 fujii@postgresql.org 292 :CBC 858 : return true;
293 : : }
294 : :
295 : : /*
296 : : * Check whether the passed slot name is valid.
297 : : *
298 : : * An error will be reported for a reserved replication slot name if
299 : : * allow_reserved_name is set to false.
300 : : *
301 : : * Slot names may consist out of [a-z0-9_]{1,NAMEDATALEN-1} which should allow
302 : : * the name to be used as a directory name on every supported OS.
303 : : *
304 : : * Returns true if the slot name is valid. Otherwise, returns false and stores
305 : : * the error code, error message, and optional hint in err_code, err_msg, and
306 : : * err_hint, respectively. The caller is responsible for freeing err_msg and
307 : : * err_hint, which are palloc'd.
308 : : */
309 : : bool
195 fujii@postgresql.org 310 :GNC 1076 : ReplicationSlotValidateNameInternal(const char *name, bool allow_reserved_name,
311 : : int *err_code, char **err_msg, char **err_hint)
312 : : {
313 : : const char *cp;
314 : :
4477 rhaas@postgresql.org 315 [ + + ]:CBC 1076 : if (strlen(name) == 0)
316 : : {
195 fujii@postgresql.org 317 : 4 : *err_code = ERRCODE_INVALID_NAME;
318 : 4 : *err_msg = psprintf(_("replication slot name \"%s\" is too short"), name);
319 : 4 : *err_hint = NULL;
4477 rhaas@postgresql.org 320 : 4 : return false;
321 : : }
322 : :
323 [ - + ]: 1072 : if (strlen(name) >= NAMEDATALEN)
324 : : {
195 fujii@postgresql.org 325 :UBC 0 : *err_code = ERRCODE_NAME_TOO_LONG;
326 : 0 : *err_msg = psprintf(_("replication slot name \"%s\" is too long"), name);
327 : 0 : *err_hint = NULL;
4477 rhaas@postgresql.org 328 : 0 : return false;
329 : : }
330 : :
4477 rhaas@postgresql.org 331 [ + + ]:CBC 20609 : for (cp = name; *cp; cp++)
332 : : {
333 [ + + - + ]: 19539 : if (!((*cp >= 'a' && *cp <= 'z')
334 [ + + + + ]: 9255 : || (*cp >= '0' && *cp <= '9')
335 [ + + ]: 1917 : || (*cp == '_')))
336 : : {
195 fujii@postgresql.org 337 : 2 : *err_code = ERRCODE_INVALID_NAME;
338 : 2 : *err_msg = psprintf(_("replication slot name \"%s\" contains invalid character"), name);
339 : 2 : *err_hint = psprintf(_("Replication slot names may only contain lower case letters, numbers, and the underscore character."));
4477 rhaas@postgresql.org 340 : 2 : return false;
341 : : }
342 : : }
343 : :
286 akapila@postgresql.o 344 [ + + + + ]:GNC 1070 : if (!allow_reserved_name && IsSlotForConflictCheck(name))
345 : : {
195 fujii@postgresql.org 346 : 1 : *err_code = ERRCODE_RESERVED_NAME;
347 : 1 : *err_msg = psprintf(_("replication slot name \"%s\" is reserved"), name);
348 : 1 : *err_hint = psprintf(_("The name \"%s\" is reserved for the conflict detection slot."),
349 : : CONFLICT_DETECTION_SLOT);
286 akapila@postgresql.o 350 : 1 : return false;
351 : : }
352 : :
4477 rhaas@postgresql.org 353 :CBC 1069 : return true;
354 : : }
355 : :
356 : : /*
357 : : * Return true if the replication slot name is "pg_conflict_detection".
358 : : */
359 : : static bool
286 akapila@postgresql.o 360 :GNC 2320 : IsSlotForConflictCheck(const char *name)
361 : : {
362 : 2320 : return (strcmp(name, CONFLICT_DETECTION_SLOT) == 0);
363 : : }
364 : :
365 : : /*
366 : : * Create a new replication slot and mark it as used by this backend.
367 : : *
368 : : * name: Name of the slot
369 : : * db_specific: logical decoding is db specific; if the slot is going to
370 : : * be used for that pass true, otherwise false.
371 : : * two_phase: If enabled, allows decoding of prepared transactions.
372 : : * repack: If true, use a slot from the pool for REPACK.
373 : : * failover: If enabled, allows the slot to be synced to standbys so
374 : : * that logical replication can be resumed after failover.
375 : : * synced: True if the slot is synchronized from the primary server.
376 : : */
377 : : void
4446 rhaas@postgresql.org 378 :CBC 718 : ReplicationSlotCreate(const char *name, bool db_specific,
379 : : ReplicationSlotPersistency persistency,
380 : : bool two_phase, bool repack, bool failover, bool synced)
381 : : {
4477 382 : 718 : ReplicationSlot *slot = NULL;
383 : : int startpoint,
384 : : endpoint;
385 : :
386 [ - + ]: 718 : Assert(MyReplicationSlot == NULL);
387 : :
388 : : /*
389 : : * The logical launcher or pg_upgrade may create or migrate an internal
390 : : * slot, so using a reserved name is allowed in these cases.
391 : : */
286 akapila@postgresql.o 392 [ + + + + ]:GNC 718 : ReplicationSlotValidateName(name, IsBinaryUpgrade || IsLogicalLauncher(),
393 : : ERROR);
394 : :
811 akapila@postgresql.o 395 [ + + ]:CBC 717 : if (failover)
396 : : {
397 : : /*
398 : : * Do not allow users to create the failover enabled slots on the
399 : : * standby as we do not support sync to the cascading standby.
400 : : *
401 : : * However, failover enabled slots can be created during slot
402 : : * synchronization because we need to retain the same values as the
403 : : * remote slot.
404 : : */
405 [ + + - + ]: 32 : if (RecoveryInProgress() && !IsSyncingReplicationSlots())
811 akapila@postgresql.o 406 [ # # ]:UBC 0 : ereport(ERROR,
407 : : errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
408 : : errmsg("cannot enable failover for a replication slot created on the standby"));
409 : :
410 : : /*
411 : : * Do not allow users to create failover enabled temporary slots,
412 : : * because temporary slots will not be synced to the standby.
413 : : *
414 : : * However, failover enabled temporary slots can be created during
415 : : * slot synchronization. See the comments atop slotsync.c for details.
416 : : */
811 akapila@postgresql.o 417 [ + + + + ]:CBC 32 : if (persistency == RS_TEMPORARY && !IsSyncingReplicationSlots())
418 [ + - ]: 1 : ereport(ERROR,
419 : : errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
420 : : errmsg("cannot enable failover for a temporary replication slot"));
421 : : }
422 : :
423 : : /*
424 : : * If some other backend ran this code concurrently with us, we'd likely
425 : : * both allocate the same slot, and that would be bad. We'd also be at
426 : : * risk of missing a name collision. Also, we don't want to try to create
427 : : * a new slot while somebody's busy cleaning up an old one, because we
428 : : * might both be monkeying with the same directory.
429 : : */
4477 rhaas@postgresql.org 430 : 716 : LWLockAcquire(ReplicationSlotAllocationLock, LW_EXCLUSIVE);
431 : :
432 : : /*
433 : : * Check for name collision (across the whole array), and identify an
434 : : * allocatable slot (in the array slice specific to our current use case:
435 : : * either general, or REPACK only). We need to hold
436 : : * ReplicationSlotControlLock in shared mode for this, so that nobody else
437 : : * can change the in_use flags while we're looking at them.
438 : : */
439 : 716 : LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
28 alvherre@kurilemu.de 440 [ + + ]:GNC 716 : startpoint = !repack ? 0 : max_replication_slots;
441 [ + + ]: 716 : endpoint = max_replication_slots + (repack ? max_repack_replication_slots : 0);
442 [ + + ]: 10527 : for (int i = 0; i < max_replication_slots + max_repack_replication_slots; i++)
443 : : {
4477 rhaas@postgresql.org 444 :CBC 9814 : ReplicationSlot *s = &ReplicationSlotCtl->replication_slots[i];
445 : :
446 [ + + + + ]: 9814 : if (s->in_use && strcmp(name, NameStr(s->data.name)) == 0)
447 [ + - ]: 3 : ereport(ERROR,
448 : : (errcode(ERRCODE_DUPLICATE_OBJECT),
449 : : errmsg("replication slot \"%s\" already exists", name)));
450 : :
28 alvherre@kurilemu.de 451 [ + + + + ]:GNC 9811 : if (i >= startpoint && i < endpoint &&
452 [ + + + + ]: 6237 : !s->in_use && slot == NULL)
4477 rhaas@postgresql.org 453 :CBC 712 : slot = s;
454 : : }
455 : 713 : LWLockRelease(ReplicationSlotControlLock);
456 : :
457 : : /* If all slots are in use, we're out of luck. */
458 [ + + ]: 713 : if (slot == NULL)
459 [ + - - + ]: 1 : ereport(ERROR,
460 : : (errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
461 : : errmsg("all replication slots are in use"),
462 : : errhint("Free one or increase \"%s\".",
463 : : repack ? "max_repack_replication_slots" : "max_replication_slots")));
464 : :
465 : : /*
466 : : * Since this slot is not in use, nobody should be looking at any part of
467 : : * it other than the in_use field unless they're trying to allocate it.
468 : : * And since we hold ReplicationSlotAllocationLock, nobody except us can
469 : : * be doing that. So it's safe to initialize the slot.
470 : : */
471 [ - + ]: 712 : Assert(!slot->in_use);
84 heikki.linnakangas@i 472 [ - + ]:GNC 712 : Assert(slot->active_proc == INVALID_PROC_NUMBER);
473 : :
474 : : /* first initialize persistent data */
3548 andres@anarazel.de 475 :CBC 712 : memset(&slot->data, 0, sizeof(ReplicationSlotPersistentData));
2094 peter@eisentraut.org 476 : 712 : namestrcpy(&slot->data.name, name);
4477 rhaas@postgresql.org 477 [ + + ]: 712 : slot->data.database = db_specific ? MyDatabaseId : InvalidOid;
3548 andres@anarazel.de 478 : 712 : slot->data.persistency = persistency;
1889 akapila@postgresql.o 479 : 712 : slot->data.two_phase = two_phase;
1756 480 : 712 : slot->data.two_phase_at = InvalidXLogRecPtr;
831 481 : 712 : slot->data.failover = failover;
811 482 : 712 : slot->data.synced = synced;
483 : :
484 : : /* and then data only present in shared memory */
3548 andres@anarazel.de 485 : 712 : slot->just_dirtied = false;
486 : 712 : slot->dirty = false;
487 : 712 : slot->effective_xmin = InvalidTransactionId;
488 : 712 : slot->effective_catalog_xmin = InvalidTransactionId;
489 : 712 : slot->candidate_catalog_xmin = InvalidTransactionId;
490 : 712 : slot->candidate_xmin_lsn = InvalidXLogRecPtr;
491 : 712 : slot->candidate_restart_valid = InvalidXLogRecPtr;
492 : 712 : slot->candidate_restart_lsn = InvalidXLogRecPtr;
964 akapila@postgresql.o 493 : 712 : slot->last_saved_confirmed_flush = InvalidXLogRecPtr;
325 akorotkov@postgresql 494 : 712 : slot->last_saved_restart_lsn = InvalidXLogRecPtr;
769 akapila@postgresql.o 495 : 712 : slot->inactive_since = 0;
158 akapila@postgresql.o 496 :GNC 712 : slot->slotsync_skip_reason = SS_SKIP_NONE;
497 : :
498 : : /*
499 : : * Create the slot on disk. We haven't actually marked the slot allocated
500 : : * yet, so no special cleanup is required if this errors out.
501 : : */
4477 rhaas@postgresql.org 502 :CBC 712 : CreateSlotOnDisk(slot);
503 : :
504 : : /*
505 : : * We need to briefly prevent any other backend from iterating over the
506 : : * slots while we flip the in_use flag. We also need to set the active
507 : : * flag while holding the ControlLock as otherwise a concurrent
508 : : * ReplicationSlotAcquire() could acquire the slot as well.
509 : : */
510 : 712 : LWLockAcquire(ReplicationSlotControlLock, LW_EXCLUSIVE);
511 : :
512 : 712 : slot->in_use = true;
513 : :
514 : : /* We can now mark the slot active, and that makes it our slot. */
3864 515 [ - + ]: 712 : SpinLockAcquire(&slot->mutex);
84 heikki.linnakangas@i 516 [ - + ]:GNC 712 : Assert(slot->active_proc == INVALID_PROC_NUMBER);
517 : 712 : slot->active_proc = MyProcNumber;
3864 rhaas@postgresql.org 518 :CBC 712 : SpinLockRelease(&slot->mutex);
519 : 712 : MyReplicationSlot = slot;
520 : :
4477 521 : 712 : LWLockRelease(ReplicationSlotControlLock);
522 : :
523 : : /*
524 : : * Create statistics entry for the new logical slot. We don't collect any
525 : : * stats for physical slots, so no need to create an entry for the same.
526 : : * See ReplicationSlotDropPtr for why we need to do this before releasing
527 : : * ReplicationSlotAllocationLock.
528 : : */
2035 akapila@postgresql.o 529 [ + + ]: 712 : if (SlotIsLogical(slot))
1490 andres@anarazel.de 530 : 511 : pgstat_create_replslot(slot);
531 : :
532 : : /*
533 : : * Now that the slot has been marked as in_use and active, it's safe to
534 : : * let somebody else try to allocate a slot.
535 : : */
4477 rhaas@postgresql.org 536 : 712 : LWLockRelease(ReplicationSlotAllocationLock);
537 : :
538 : : /* Let everybody know we've modified this slot */
3206 alvherre@alvh.no-ip. 539 : 712 : ConditionVariableBroadcast(&slot->active_cv);
4477 rhaas@postgresql.org 540 : 712 : }
541 : :
542 : : /*
543 : : * Search for the named replication slot.
544 : : *
545 : : * Return the replication slot if found, otherwise NULL.
546 : : */
547 : : ReplicationSlot *
1834 akapila@postgresql.o 548 : 2110 : SearchNamedReplicationSlot(const char *name, bool need_lock)
549 : : {
550 : : int i;
551 : 2110 : ReplicationSlot *slot = NULL;
552 : :
553 [ + + ]: 2110 : if (need_lock)
554 : 641 : LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
555 : :
28 alvherre@kurilemu.de 556 [ + + ]:GNC 11025 : for (i = 0; i < max_replication_slots + max_repack_replication_slots; i++)
557 : : {
4477 rhaas@postgresql.org 558 :CBC 10487 : ReplicationSlot *s = &ReplicationSlotCtl->replication_slots[i];
559 : :
560 [ + + + + ]: 10487 : if (s->in_use && strcmp(name, NameStr(s->data.name)) == 0)
561 : : {
562 : 1572 : slot = s;
563 : 1572 : break;
564 : : }
565 : : }
566 : :
1834 akapila@postgresql.o 567 [ + + ]: 2110 : if (need_lock)
568 : 641 : LWLockRelease(ReplicationSlotControlLock);
569 : :
2146 fujii@postgresql.org 570 : 2110 : return slot;
571 : : }
572 : :
573 : : /*
574 : : * Return the index of the replication slot in
575 : : * ReplicationSlotCtl->replication_slots.
576 : : *
577 : : * This is mainly useful to have an efficient key for storing replication slot
578 : : * stats.
579 : : */
580 : : int
1490 andres@anarazel.de 581 : 8232 : ReplicationSlotIndex(ReplicationSlot *slot)
582 : : {
583 [ + - - + ]: 8232 : Assert(slot >= ReplicationSlotCtl->replication_slots &&
584 : : slot < ReplicationSlotCtl->replication_slots +
585 : : (max_replication_slots + max_repack_replication_slots));
586 : :
587 : 8232 : return slot - ReplicationSlotCtl->replication_slots;
588 : : }
589 : :
590 : : /*
591 : : * If the slot at 'index' is unused, return false. Otherwise 'name' is set to
592 : : * the slot's name and true is returned.
593 : : *
594 : : * This likely is only useful for pgstat_replslot.c during shutdown, in other
595 : : * cases there are obvious TOCTOU issues.
596 : : */
597 : : bool
1305 598 : 110 : ReplicationSlotName(int index, Name name)
599 : : {
600 : : ReplicationSlot *slot;
601 : : bool found;
602 : :
603 : 110 : slot = &ReplicationSlotCtl->replication_slots[index];
604 : :
605 : : /*
606 : : * Ensure that the slot cannot be dropped while we copy the name. Don't
607 : : * need the spinlock as the name of an existing slot cannot change.
608 : : */
609 : 110 : LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
610 : 110 : found = slot->in_use;
611 [ + - ]: 110 : if (slot->in_use)
612 : 110 : namestrcpy(name, NameStr(slot->data.name));
613 : 110 : LWLockRelease(ReplicationSlotControlLock);
614 : :
615 : 110 : return found;
616 : : }
617 : :
618 : : /*
619 : : * Find a previously created slot and mark it as used by this process.
620 : : *
621 : : * An error is raised if nowait is true and the slot is currently in use. If
622 : : * nowait is false, we sleep until the slot is released by the owning process.
623 : : *
624 : : * An error is raised if error_if_invalid is true and the slot is found to
625 : : * be invalid. It should always be set to true, except when we are temporarily
626 : : * acquiring the slot and don't intend to change it.
627 : : */
628 : : void
459 akapila@postgresql.o 629 : 1387 : ReplicationSlotAcquire(const char *name, bool nowait, bool error_if_invalid)
630 : : {
631 : : ReplicationSlot *s;
632 : : ProcNumber active_proc;
633 : : int active_pid;
634 : :
1285 peter@eisentraut.org 635 [ + - ]: 1387 : Assert(name != NULL);
636 : :
2146 fujii@postgresql.org 637 : 1387 : retry:
638 [ - + ]: 1387 : Assert(MyReplicationSlot == NULL);
639 : :
640 : 1387 : LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
641 : :
642 : : /* Check if the slot exists with the given name. */
1789 alvherre@alvh.no-ip. 643 : 1387 : s = SearchNamedReplicationSlot(name, false);
2146 fujii@postgresql.org 644 [ + + - + ]: 1387 : if (s == NULL || !s->in_use)
645 : : {
646 : 10 : LWLockRelease(ReplicationSlotControlLock);
647 : :
4477 rhaas@postgresql.org 648 [ + - ]: 10 : ereport(ERROR,
649 : : (errcode(ERRCODE_UNDEFINED_OBJECT),
650 : : errmsg("replication slot \"%s\" does not exist",
651 : : name)));
652 : : }
653 : :
654 : : /*
655 : : * Do not allow users to acquire the reserved slot. This scenario may
656 : : * occur if the launcher that owns the slot has terminated unexpectedly
657 : : * due to an error, and a backend process attempts to reuse the slot.
658 : : */
286 akapila@postgresql.o 659 [ + + - + ]:GNC 1377 : if (!IsLogicalLauncher() && IsSlotForConflictCheck(name))
286 akapila@postgresql.o 660 [ # # ]:UNC 0 : ereport(ERROR,
661 : : errcode(ERRCODE_UNDEFINED_OBJECT),
662 : : errmsg("cannot acquire replication slot \"%s\"", name),
663 : : errdetail("The slot is reserved for conflict detection and can only be acquired by logical replication launcher."));
664 : :
665 : : /*
666 : : * This is the slot we want; check if it's active under some other
667 : : * process. In single user mode, we don't need this check.
668 : : */
2146 fujii@postgresql.org 669 [ + + ]:CBC 1377 : if (IsUnderPostmaster)
670 : : {
671 : : /*
672 : : * Get ready to sleep on the slot in case it is active. (We may end
673 : : * up not sleeping, but we don't want to do this while holding the
674 : : * spinlock.)
675 : : */
1789 alvherre@alvh.no-ip. 676 [ + + ]: 1372 : if (!nowait)
2146 fujii@postgresql.org 677 : 294 : ConditionVariablePrepareToSleep(&s->active_cv);
678 : :
679 : : /*
680 : : * It is important to reset the inactive_since under spinlock here to
681 : : * avoid race conditions with slot invalidation. See comments related
682 : : * to inactive_since in InvalidatePossiblyObsoleteSlot.
683 : : */
684 [ - + ]: 1372 : SpinLockAcquire(&s->mutex);
84 heikki.linnakangas@i 685 [ + + ]:GNC 1372 : if (s->active_proc == INVALID_PROC_NUMBER)
686 : 1215 : s->active_proc = MyProcNumber;
687 : 1372 : active_proc = s->active_proc;
440 akapila@postgresql.o 688 :CBC 1372 : ReplicationSlotSetInactiveSince(s, 0, false);
2146 fujii@postgresql.org 689 : 1372 : SpinLockRelease(&s->mutex);
690 : : }
691 : : else
692 : : {
84 heikki.linnakangas@i 693 :GNC 5 : s->active_proc = active_proc = MyProcNumber;
440 akapila@postgresql.o 694 :CBC 5 : ReplicationSlotSetInactiveSince(s, 0, true);
695 : : }
84 heikki.linnakangas@i 696 :GNC 1377 : active_pid = GetPGProcByNumber(active_proc)->pid;
2146 fujii@postgresql.org 697 :CBC 1377 : LWLockRelease(ReplicationSlotControlLock);
698 : :
699 : : /*
700 : : * If we found the slot but it's already active in another process, we
701 : : * wait until the owning process signals us that it's been released, or
702 : : * error out.
703 : : */
84 heikki.linnakangas@i 704 [ - + ]:GNC 1377 : if (active_proc != MyProcNumber)
705 : : {
1789 alvherre@alvh.no-ip. 706 [ # # ]:UBC 0 : if (!nowait)
707 : : {
708 : : /* Wait here until we get signaled, and then restart */
1786 709 : 0 : ConditionVariableSleep(&s->active_cv,
710 : : WAIT_EVENT_REPLICATION_SLOT_DROP);
711 : 0 : ConditionVariableCancelSleep();
712 : 0 : goto retry;
713 : : }
714 : :
715 [ # # ]: 0 : ereport(ERROR,
716 : : (errcode(ERRCODE_OBJECT_IN_USE),
717 : : errmsg("replication slot \"%s\" is active for PID %d",
718 : : NameStr(s->data.name), active_pid)));
719 : : }
1789 alvherre@alvh.no-ip. 720 [ + + ]:CBC 1377 : else if (!nowait)
1819 tgl@sss.pgh.pa.us 721 : 294 : ConditionVariableCancelSleep(); /* no sleep needed after all */
722 : :
723 : : /* We made this slot active, so it's ours now. */
2146 fujii@postgresql.org 724 : 1377 : MyReplicationSlot = s;
725 : :
726 : : /*
727 : : * We need to check for invalidation after making the slot ours to avoid
728 : : * the possible race condition with the checkpointer that can otherwise
729 : : * invalidate the slot immediately after the check.
730 : : */
432 akapila@postgresql.o 731 [ + + + + ]: 1377 : if (error_if_invalid && s->data.invalidated != RS_INVAL_NONE)
732 [ + - ]: 7 : ereport(ERROR,
733 : : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
734 : : errmsg("can no longer access replication slot \"%s\"",
735 : : NameStr(s->data.name)),
736 : : errdetail("This replication slot has been invalidated due to \"%s\".",
737 : : GetSlotInvalidationCauseName(s->data.invalidated)));
738 : :
739 : : /* Let everybody know we've modified this slot */
740 : 1370 : ConditionVariableBroadcast(&s->active_cv);
741 : :
742 : : /*
743 : : * The call to pgstat_acquire_replslot() protects against stats for a
744 : : * different slot, from before a restart or such, being present during
745 : : * pgstat_report_replslot().
746 : : */
1490 andres@anarazel.de 747 [ + + ]: 1370 : if (SlotIsLogical(s))
748 : 1143 : pgstat_acquire_replslot(s);
749 : :
750 : :
896 akapila@postgresql.o 751 [ + + ]: 1370 : if (am_walsender)
752 : : {
753 [ + - + - : 942 : ereport(log_replication_commands ? LOG : DEBUG1,
+ + ]
754 : : SlotIsLogical(s)
755 : : ? errmsg("acquired logical replication slot \"%s\"",
756 : : NameStr(s->data.name))
757 : : : errmsg("acquired physical replication slot \"%s\"",
758 : : NameStr(s->data.name)));
759 : : }
4477 rhaas@postgresql.org 760 : 1370 : }
761 : :
762 : : /*
763 : : * Release the replication slot that this backend considers to own.
764 : : *
765 : : * This or another backend can re-acquire the slot later.
766 : : * Resources this slot requires will be preserved.
767 : : */
768 : : void
769 : 1665 : ReplicationSlotRelease(void)
770 : : {
771 : 1665 : ReplicationSlot *slot = MyReplicationSlot;
896 akapila@postgresql.o 772 : 1665 : char *slotname = NULL; /* keep compiler quiet */
773 : : bool is_logical;
771 774 : 1665 : TimestampTz now = 0;
775 : :
84 heikki.linnakangas@i 776 [ + - - + ]:GNC 1665 : Assert(slot != NULL && slot->active_proc != INVALID_PROC_NUMBER);
777 : :
133 msawada@postgresql.o 778 : 1665 : is_logical = SlotIsLogical(slot);
779 : :
896 akapila@postgresql.o 780 [ + + ]:CBC 1665 : if (am_walsender)
781 : 1169 : slotname = pstrdup(NameStr(slot->data.name));
782 : :
4446 rhaas@postgresql.org 783 [ + + ]: 1665 : if (slot->data.persistency == RS_EPHEMERAL)
784 : : {
785 : : /*
786 : : * Delete the slot. There is no !PANIC case where this is allowed to
787 : : * fail, all that may happen is an incomplete cleanup of the on-disk
788 : : * data.
789 : : */
790 : 6 : ReplicationSlotDropAcquired();
791 : :
792 : : /*
793 : : * Request to disable logical decoding, even though this slot may not
794 : : * have been the last logical slot. The checkpointer will verify if
795 : : * logical decoding should actually be disabled.
796 : : */
133 msawada@postgresql.o 797 [ + - ]:GNC 6 : if (is_logical)
798 : 6 : RequestDisableLogicalDecoding();
799 : : }
800 : :
801 : : /*
802 : : * If slot needed to temporarily restrain both data and catalog xmin to
803 : : * create the catalog snapshot, remove that temporary constraint.
804 : : * Snapshots can only be exported while the initial snapshot is still
805 : : * acquired.
806 : : */
3299 andres@anarazel.de 807 [ + + ]:CBC 1665 : if (!TransactionIdIsValid(slot->data.xmin) &&
808 [ + + ]: 1633 : TransactionIdIsValid(slot->effective_xmin))
809 : : {
810 [ - + ]: 213 : SpinLockAcquire(&slot->mutex);
811 : 213 : slot->effective_xmin = InvalidTransactionId;
812 : 213 : SpinLockRelease(&slot->mutex);
813 : 213 : ReplicationSlotsComputeRequiredXmin(false);
814 : : }
815 : :
816 : : /*
817 : : * Set the time since the slot has become inactive. We get the current
818 : : * time beforehand to avoid system call while holding the spinlock.
819 : : */
760 akapila@postgresql.o 820 : 1665 : now = GetCurrentTimestamp();
821 : :
3206 alvherre@alvh.no-ip. 822 [ + + ]: 1665 : if (slot->data.persistency == RS_PERSISTENT)
823 : : {
824 : : /*
825 : : * Mark persistent slot inactive. We're not freeing it, just
826 : : * disconnecting, but wake up others that may be waiting for it.
827 : : */
828 [ - + ]: 1344 : SpinLockAcquire(&slot->mutex);
84 heikki.linnakangas@i 829 :GNC 1344 : slot->active_proc = INVALID_PROC_NUMBER;
454 akapila@postgresql.o 830 :CBC 1344 : ReplicationSlotSetInactiveSince(slot, now, false);
3206 alvherre@alvh.no-ip. 831 : 1344 : SpinLockRelease(&slot->mutex);
832 : 1344 : ConditionVariableBroadcast(&slot->active_cv);
833 : : }
834 : : else
454 akapila@postgresql.o 835 : 321 : ReplicationSlotSetInactiveSince(slot, now, true);
836 : :
4446 rhaas@postgresql.org 837 : 1665 : MyReplicationSlot = NULL;
838 : :
839 : : /* might not have been set when we've been a plain slot */
1636 alvherre@alvh.no-ip. 840 : 1665 : LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
1996 841 : 1665 : MyProc->statusFlags &= ~PROC_IN_LOGICAL_DECODING;
842 : 1665 : ProcGlobal->statusFlags[MyProc->pgxactoff] = MyProc->statusFlags;
4446 rhaas@postgresql.org 843 : 1665 : LWLockRelease(ProcArrayLock);
844 : :
896 akapila@postgresql.o 845 [ + + ]: 1665 : if (am_walsender)
846 : : {
847 [ + - + - : 1169 : ereport(log_replication_commands ? LOG : DEBUG1,
+ + ]
848 : : is_logical
849 : : ? errmsg("released logical replication slot \"%s\"",
850 : : slotname)
851 : : : errmsg("released physical replication slot \"%s\"",
852 : : slotname));
853 : :
854 : 1169 : pfree(slotname);
855 : : }
4477 rhaas@postgresql.org 856 : 1665 : }
857 : :
858 : : /*
859 : : * Cleanup temporary slots created in current session.
860 : : *
861 : : * Cleanup only synced temporary slots if 'synced_only' is true, else
862 : : * cleanup all temporary slots.
863 : : *
864 : : * If it drops the last logical slot in the cluster, requests to disable
865 : : * logical decoding.
866 : : */
867 : : void
740 akapila@postgresql.o 868 : 54110 : ReplicationSlotCleanup(bool synced_only)
869 : : {
870 : : int i;
871 : : bool found_valid_logicalslot;
133 msawada@postgresql.o 872 :GNC 54110 : bool dropped_logical = false;
873 : :
3435 peter_e@gmx.net 874 [ + - ]:CBC 54110 : Assert(MyReplicationSlot == NULL);
875 : :
3206 alvherre@alvh.no-ip. 876 : 54110 : restart:
133 msawada@postgresql.o 877 :GNC 54268 : found_valid_logicalslot = false;
3206 alvherre@alvh.no-ip. 878 :CBC 54268 : LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
28 alvherre@kurilemu.de 879 [ + + ]:GNC 860193 : for (i = 0; i < max_replication_slots + max_repack_replication_slots; i++)
880 : : {
3435 peter_e@gmx.net 881 :CBC 806083 : ReplicationSlot *s = &ReplicationSlotCtl->replication_slots[i];
882 : :
3206 alvherre@alvh.no-ip. 883 [ + + ]: 806083 : if (!s->in_use)
884 : 790728 : continue;
885 : :
886 [ + + ]: 15355 : SpinLockAcquire(&s->mutex);
887 : :
133 msawada@postgresql.o 888 :GNC 30710 : found_valid_logicalslot |=
889 [ + + + + ]: 15355 : (SlotIsLogical(s) && s->data.invalidated == RS_INVAL_NONE);
890 : :
84 heikki.linnakangas@i 891 [ + + ]: 15355 : if ((s->active_proc == MyProcNumber &&
740 akapila@postgresql.o 892 [ - + - - ]:CBC 158 : (!synced_only || s->data.synced)))
893 : : {
3206 alvherre@alvh.no-ip. 894 [ - + ]: 158 : Assert(s->data.persistency == RS_TEMPORARY);
895 : 158 : SpinLockRelease(&s->mutex);
896 : 158 : LWLockRelease(ReplicationSlotControlLock); /* avoid deadlock */
897 : :
133 msawada@postgresql.o 898 [ + + ]:GNC 158 : if (SlotIsLogical(s))
899 : 11 : dropped_logical = true;
900 : :
3435 peter_e@gmx.net 901 :CBC 158 : ReplicationSlotDropPtr(s);
902 : :
3206 alvherre@alvh.no-ip. 903 : 158 : ConditionVariableBroadcast(&s->active_cv);
904 : 158 : goto restart;
905 : : }
906 : : else
907 : 15197 : SpinLockRelease(&s->mutex);
908 : : }
909 : :
910 : 54110 : LWLockRelease(ReplicationSlotControlLock);
911 : :
133 msawada@postgresql.o 912 [ + + + + ]:GNC 54110 : if (dropped_logical && !found_valid_logicalslot)
913 : 4 : RequestDisableLogicalDecoding();
3435 peter_e@gmx.net 914 :CBC 54110 : }
915 : :
916 : : /*
917 : : * Permanently drop replication slot identified by the passed in name.
918 : : */
919 : : void
3206 alvherre@alvh.no-ip. 920 : 442 : ReplicationSlotDrop(const char *name, bool nowait)
921 : : {
922 : : bool is_logical;
923 : :
4446 rhaas@postgresql.org 924 [ - + ]: 442 : Assert(MyReplicationSlot == NULL);
925 : :
459 akapila@postgresql.o 926 : 442 : ReplicationSlotAcquire(name, nowait, false);
927 : :
928 : : /*
929 : : * Do not allow users to drop the slots which are currently being synced
930 : : * from the primary to the standby.
931 : : */
811 932 [ + + + + ]: 434 : if (RecoveryInProgress() && MyReplicationSlot->data.synced)
933 [ + - ]: 1 : ereport(ERROR,
934 : : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
935 : : errmsg("cannot drop replication slot \"%s\"", name),
936 : : errdetail("This replication slot is being synchronized from the primary server."));
937 : :
133 msawada@postgresql.o 938 :GNC 433 : is_logical = SlotIsLogical(MyReplicationSlot);
939 : :
4446 rhaas@postgresql.org 940 :CBC 433 : ReplicationSlotDropAcquired();
941 : :
133 msawada@postgresql.o 942 [ + + ]:GNC 433 : if (is_logical)
943 : 413 : RequestDisableLogicalDecoding();
4446 rhaas@postgresql.org 944 :CBC 433 : }
945 : :
946 : : /*
947 : : * Change the definition of the slot identified by the specified name.
948 : : *
949 : : * Altering the two_phase property of a slot requires caution on the
950 : : * client-side. Enabling it at any random point during decoding has the
951 : : * risk that transactions prepared before this change may be skipped by
952 : : * the decoder, leading to missing prepare records on the client. So, we
953 : : * enable it for subscription related slots only once the initial tablesync
954 : : * is finished. See comments atop worker.c. Disabling it is safe only when
955 : : * there are no pending prepared transaction, otherwise, the changes of
956 : : * already prepared transactions can be replicated again along with their
957 : : * corresponding commit leading to duplicate data or errors.
958 : : */
959 : : void
650 akapila@postgresql.o 960 : 7 : ReplicationSlotAlter(const char *name, const bool *failover,
961 : : const bool *two_phase)
962 : : {
963 : 7 : bool update_slot = false;
964 : :
827 965 [ - + ]: 7 : Assert(MyReplicationSlot == NULL);
650 966 [ + + - + ]: 7 : Assert(failover || two_phase);
967 : :
459 968 : 7 : ReplicationSlotAcquire(name, false, true);
969 : :
827 970 [ - + ]: 6 : if (SlotIsPhysical(MyReplicationSlot))
827 akapila@postgresql.o 971 [ # # ]:UBC 0 : ereport(ERROR,
972 : : errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
973 : : errmsg("cannot use %s with a physical replication slot",
974 : : "ALTER_REPLICATION_SLOT"));
975 : :
811 akapila@postgresql.o 976 [ + + ]:CBC 6 : if (RecoveryInProgress())
977 : : {
978 : : /*
979 : : * Do not allow users to alter the slots which are currently being
980 : : * synced from the primary to the standby.
981 : : */
982 [ + - ]: 1 : if (MyReplicationSlot->data.synced)
983 [ + - ]: 1 : ereport(ERROR,
984 : : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
985 : : errmsg("cannot alter replication slot \"%s\"", name),
986 : : errdetail("This replication slot is being synchronized from the primary server."));
987 : :
988 : : /*
989 : : * Do not allow users to enable failover on the standby as we do not
990 : : * support sync to the cascading standby.
991 : : */
650 akapila@postgresql.o 992 [ # # # # ]:UBC 0 : if (failover && *failover)
811 993 [ # # ]: 0 : ereport(ERROR,
994 : : errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
995 : : errmsg("cannot enable failover for a replication slot"
996 : : " on the standby"));
997 : : }
998 : :
650 akapila@postgresql.o 999 [ + + ]:CBC 5 : if (failover)
1000 : : {
1001 : : /*
1002 : : * Do not allow users to enable failover for temporary slots as we do
1003 : : * not support syncing temporary slots to the standby.
1004 : : */
1005 [ + + - + ]: 4 : if (*failover && MyReplicationSlot->data.persistency == RS_TEMPORARY)
650 akapila@postgresql.o 1006 [ # # ]:UBC 0 : ereport(ERROR,
1007 : : errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
1008 : : errmsg("cannot enable failover for a temporary replication slot"));
1009 : :
650 akapila@postgresql.o 1010 [ + - ]:CBC 4 : if (MyReplicationSlot->data.failover != *failover)
1011 : : {
1012 [ - + ]: 4 : SpinLockAcquire(&MyReplicationSlot->mutex);
1013 : 4 : MyReplicationSlot->data.failover = *failover;
1014 : 4 : SpinLockRelease(&MyReplicationSlot->mutex);
1015 : :
1016 : 4 : update_slot = true;
1017 : : }
1018 : : }
1019 : :
1020 [ + + + - ]: 5 : if (two_phase && MyReplicationSlot->data.two_phase != *two_phase)
1021 : : {
818 1022 [ - + ]: 1 : SpinLockAcquire(&MyReplicationSlot->mutex);
650 1023 : 1 : MyReplicationSlot->data.two_phase = *two_phase;
818 1024 : 1 : SpinLockRelease(&MyReplicationSlot->mutex);
1025 : :
650 1026 : 1 : update_slot = true;
1027 : : }
1028 : :
1029 [ + - ]: 5 : if (update_slot)
1030 : : {
818 1031 : 5 : ReplicationSlotMarkDirty();
1032 : 5 : ReplicationSlotSave();
1033 : : }
1034 : :
827 1035 : 5 : ReplicationSlotRelease();
1036 : 5 : }
1037 : :
1038 : : /*
1039 : : * Permanently drop the currently acquired replication slot.
1040 : : */
1041 : : void
4446 rhaas@postgresql.org 1042 : 451 : ReplicationSlotDropAcquired(void)
1043 : : {
1044 : 451 : ReplicationSlot *slot = MyReplicationSlot;
1045 : :
1046 [ - + ]: 451 : Assert(MyReplicationSlot != NULL);
1047 : :
1048 : : /* slot isn't acquired anymore */
1049 : 451 : MyReplicationSlot = NULL;
1050 : :
3435 peter_e@gmx.net 1051 : 451 : ReplicationSlotDropPtr(slot);
1052 : 451 : }
1053 : :
1054 : : /*
1055 : : * Permanently drop the replication slot which will be released by the point
1056 : : * this function returns.
1057 : : */
1058 : : static void
1059 : 609 : ReplicationSlotDropPtr(ReplicationSlot *slot)
1060 : : {
1061 : : char path[MAXPGPATH];
1062 : : char tmppath[MAXPGPATH];
1063 : :
1064 : : /*
1065 : : * If some other backend ran this code concurrently with us, we might try
1066 : : * to delete a slot with a certain name while someone else was trying to
1067 : : * create a slot with the same name.
1068 : : */
4477 rhaas@postgresql.org 1069 : 609 : LWLockAcquire(ReplicationSlotAllocationLock, LW_EXCLUSIVE);
1070 : :
1071 : : /* Generate pathnames. */
613 michael@paquier.xyz 1072 : 609 : sprintf(path, "%s/%s", PG_REPLSLOT_DIR, NameStr(slot->data.name));
1073 : 609 : sprintf(tmppath, "%s/%s.tmp", PG_REPLSLOT_DIR, NameStr(slot->data.name));
1074 : :
1075 : : /*
1076 : : * Rename the slot directory on disk, so that we'll no longer recognize
1077 : : * this as a valid slot. Note that if this fails, we've got to mark the
1078 : : * slot inactive before bailing out. If we're dropping an ephemeral or a
1079 : : * temporary slot, we better never fail hard as the caller won't expect
1080 : : * the slot to survive and this might get called during error handling.
1081 : : */
4446 rhaas@postgresql.org 1082 [ + - ]: 609 : if (rename(path, tmppath) == 0)
1083 : : {
1084 : : /*
1085 : : * We need to fsync() the directory we just renamed and its parent to
1086 : : * make sure that our changes are on disk in a crash-safe fashion. If
1087 : : * fsync() fails, we can't be sure whether the changes are on disk or
1088 : : * not. For now, we handle that by panicking;
1089 : : * StartupReplicationSlots() will try to straighten it out after
1090 : : * restart.
1091 : : */
1092 : 609 : START_CRIT_SECTION();
1093 : 609 : fsync_fname(tmppath, true);
613 michael@paquier.xyz 1094 : 609 : fsync_fname(PG_REPLSLOT_DIR, true);
4446 rhaas@postgresql.org 1095 [ - + ]: 609 : END_CRIT_SECTION();
1096 : : }
1097 : : else
1098 : : {
3435 peter_e@gmx.net 1099 :UBC 0 : bool fail_softly = slot->data.persistency != RS_PERSISTENT;
1100 : :
4477 rhaas@postgresql.org 1101 [ # # ]: 0 : SpinLockAcquire(&slot->mutex);
84 heikki.linnakangas@i 1102 :UNC 0 : slot->active_proc = INVALID_PROC_NUMBER;
4477 rhaas@postgresql.org 1103 :UBC 0 : SpinLockRelease(&slot->mutex);
1104 : :
1105 : : /* wake up anyone waiting on this slot */
3206 alvherre@alvh.no-ip. 1106 : 0 : ConditionVariableBroadcast(&slot->active_cv);
1107 : :
4446 rhaas@postgresql.org 1108 [ # # # # ]: 0 : ereport(fail_softly ? WARNING : ERROR,
1109 : : (errcode_for_file_access(),
1110 : : errmsg("could not rename file \"%s\" to \"%s\": %m",
1111 : : path, tmppath)));
1112 : : }
1113 : :
1114 : : /*
1115 : : * The slot is definitely gone. Lock out concurrent scans of the array
1116 : : * long enough to kill it. It's OK to clear the active PID here without
1117 : : * grabbing the mutex because nobody else can be scanning the array here,
1118 : : * and nobody can be attached to this slot and thus access it without
1119 : : * scanning the array.
1120 : : *
1121 : : * Also wake up processes waiting for it.
1122 : : */
4477 rhaas@postgresql.org 1123 :CBC 609 : LWLockAcquire(ReplicationSlotControlLock, LW_EXCLUSIVE);
84 heikki.linnakangas@i 1124 :GNC 609 : slot->active_proc = INVALID_PROC_NUMBER;
4477 rhaas@postgresql.org 1125 :CBC 609 : slot->in_use = false;
1126 : 609 : LWLockRelease(ReplicationSlotControlLock);
3206 alvherre@alvh.no-ip. 1127 : 609 : ConditionVariableBroadcast(&slot->active_cv);
1128 : :
1129 : : /*
1130 : : * Slot is dead and doesn't prevent resource removal anymore, recompute
1131 : : * limits.
1132 : : */
4446 rhaas@postgresql.org 1133 : 609 : ReplicationSlotsComputeRequiredXmin(false);
4477 1134 : 609 : ReplicationSlotsComputeRequiredLSN();
1135 : :
1136 : : /*
1137 : : * If removing the directory fails, the worst thing that will happen is
1138 : : * that the user won't be able to create a new slot with the same name
1139 : : * until the next server restart. We warn about it, but that's all.
1140 : : */
1141 [ - + ]: 609 : if (!rmtree(tmppath, true))
4477 rhaas@postgresql.org 1142 [ # # ]:UBC 0 : ereport(WARNING,
1143 : : (errmsg("could not remove directory \"%s\"", tmppath)));
1144 : :
1145 : : /*
1146 : : * Drop the statistics entry for the replication slot. Do this while
1147 : : * holding ReplicationSlotAllocationLock so that we don't drop a
1148 : : * statistics entry for another slot with the same name just created in
1149 : : * another session.
1150 : : */
2035 akapila@postgresql.o 1151 [ + + ]:CBC 609 : if (SlotIsLogical(slot))
1490 andres@anarazel.de 1152 : 441 : pgstat_drop_replslot(slot);
1153 : :
1154 : : /*
1155 : : * We release this at the very end, so that nobody starts trying to create
1156 : : * a slot while we're still cleaning up the detritus of the old one.
1157 : : */
4477 rhaas@postgresql.org 1158 : 609 : LWLockRelease(ReplicationSlotAllocationLock);
1159 : 609 : }
1160 : :
1161 : : /*
1162 : : * Serialize the currently acquired slot's state from memory to disk, thereby
1163 : : * guaranteeing the current state will survive a crash.
1164 : : */
1165 : : void
1166 : 1487 : ReplicationSlotSave(void)
1167 : : {
1168 : : char path[MAXPGPATH];
1169 : :
1170 [ - + ]: 1487 : Assert(MyReplicationSlot != NULL);
1171 : :
613 michael@paquier.xyz 1172 : 1487 : sprintf(path, "%s/%s", PG_REPLSLOT_DIR, NameStr(MyReplicationSlot->data.name));
4477 rhaas@postgresql.org 1173 : 1487 : SaveSlotToPath(MyReplicationSlot, path, ERROR);
1174 : 1487 : }
1175 : :
1176 : : /*
1177 : : * Signal that it would be useful if the currently acquired slot would be
1178 : : * flushed out to disk.
1179 : : *
1180 : : * Note that the actual flush to disk can be delayed for a long time, if
1181 : : * required for correctness explicitly do a ReplicationSlotSave().
1182 : : */
1183 : : void
1184 : 43864 : ReplicationSlotMarkDirty(void)
1185 : : {
3864 1186 : 43864 : ReplicationSlot *slot = MyReplicationSlot;
1187 : :
4477 1188 [ - + ]: 43864 : Assert(MyReplicationSlot != NULL);
1189 : :
3864 1190 [ - + ]: 43864 : SpinLockAcquire(&slot->mutex);
1191 : 43864 : MyReplicationSlot->just_dirtied = true;
1192 : 43864 : MyReplicationSlot->dirty = true;
1193 : 43864 : SpinLockRelease(&slot->mutex);
4477 1194 : 43864 : }
1195 : :
1196 : : /*
1197 : : * Convert a slot that's marked as RS_EPHEMERAL or RS_TEMPORARY to a
1198 : : * RS_PERSISTENT slot, guaranteeing it will be there after an eventual crash.
1199 : : */
1200 : : void
4446 1201 : 491 : ReplicationSlotPersist(void)
1202 : : {
1203 : 491 : ReplicationSlot *slot = MyReplicationSlot;
1204 : :
1205 [ - + ]: 491 : Assert(slot != NULL);
1206 [ - + ]: 491 : Assert(slot->data.persistency != RS_PERSISTENT);
1207 : :
3864 1208 [ - + ]: 491 : SpinLockAcquire(&slot->mutex);
1209 : 491 : slot->data.persistency = RS_PERSISTENT;
1210 : 491 : SpinLockRelease(&slot->mutex);
1211 : :
4446 1212 : 491 : ReplicationSlotMarkDirty();
1213 : 491 : ReplicationSlotSave();
1214 : 491 : }
1215 : :
1216 : : /*
1217 : : * Compute the oldest xmin across all slots and store it in the ProcArray.
1218 : : *
1219 : : * If already_locked is true, both the ReplicationSlotControlLock and the
1220 : : * ProcArrayLock have already been acquired exclusively. It is crucial that the
1221 : : * caller first acquires the ReplicationSlotControlLock, followed by the
1222 : : * ProcArrayLock, to prevent any undetectable deadlocks since this function
1223 : : * acquires them in that order.
1224 : : */
1225 : : void
1226 : 2612 : ReplicationSlotsComputeRequiredXmin(bool already_locked)
1227 : : {
1228 : : int i;
4477 1229 : 2612 : TransactionId agg_xmin = InvalidTransactionId;
4446 1230 : 2612 : TransactionId agg_catalog_xmin = InvalidTransactionId;
1231 : :
4477 1232 [ - + ]: 2612 : Assert(ReplicationSlotCtl != NULL);
126 msawada@postgresql.o 1233 [ + + + - : 2612 : Assert(!already_locked ||
- + ]
1234 : : (LWLockHeldByMeInMode(ReplicationSlotControlLock, LW_EXCLUSIVE) &&
1235 : : LWLockHeldByMeInMode(ProcArrayLock, LW_EXCLUSIVE)));
1236 : :
1237 : : /*
1238 : : * Hold the ReplicationSlotControlLock until after updating the slot xmin
1239 : : * values, so no backend updates the initial xmin for newly created slot
1240 : : * concurrently. A shared lock is used here to minimize lock contention,
1241 : : * especially when many slots exist and advancements occur frequently.
1242 : : * This is safe since an exclusive lock is taken during initial slot xmin
1243 : : * update in slot creation.
1244 : : *
1245 : : * One might think that we can hold the ProcArrayLock exclusively and
1246 : : * update the slot xmin values, but it could increase lock contention on
1247 : : * the ProcArrayLock, which is not great since this function can be called
1248 : : * at non-negligible frequency.
1249 : : *
1250 : : * Concurrent invocation of this function may cause the computed slot xmin
1251 : : * to regress. However, this is harmless because tuples prior to the most
1252 : : * recent xmin are no longer useful once advancement occurs (see
1253 : : * LogicalConfirmReceivedLocation where the slot's xmin value is flushed
1254 : : * before updating the effective_xmin). Thus, such regression merely
1255 : : * prevents VACUUM from prematurely removing tuples without causing the
1256 : : * early deletion of required data.
1257 : : */
1258 [ + + ]: 2612 : if (!already_locked)
1259 : 2100 : LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
1260 : :
28 alvherre@kurilemu.de 1261 [ + + ]:GNC 39710 : for (i = 0; i < max_replication_slots + max_repack_replication_slots; i++)
1262 : : {
4477 rhaas@postgresql.org 1263 :CBC 37098 : ReplicationSlot *s = &ReplicationSlotCtl->replication_slots[i];
1264 : : TransactionId effective_xmin;
1265 : : TransactionId effective_catalog_xmin;
1266 : : bool invalidated;
1267 : :
1268 [ + + ]: 37098 : if (!s->in_use)
1269 : 34598 : continue;
1270 : :
3864 1271 [ + + ]: 2500 : SpinLockAcquire(&s->mutex);
1272 : 2500 : effective_xmin = s->effective_xmin;
1273 : 2500 : effective_catalog_xmin = s->effective_catalog_xmin;
1124 andres@anarazel.de 1274 : 2500 : invalidated = s->data.invalidated != RS_INVAL_NONE;
3864 rhaas@postgresql.org 1275 : 2500 : SpinLockRelease(&s->mutex);
1276 : :
1277 : : /* invalidated slots need not apply */
1260 alvherre@alvh.no-ip. 1278 [ + + ]: 2500 : if (invalidated)
1279 : 26 : continue;
1280 : :
1281 : : /* check the data xmin */
4477 rhaas@postgresql.org 1282 [ + + + + ]: 2474 : if (TransactionIdIsValid(effective_xmin) &&
1283 [ - + ]: 5 : (!TransactionIdIsValid(agg_xmin) ||
1284 : 5 : TransactionIdPrecedes(effective_xmin, agg_xmin)))
1285 : 331 : agg_xmin = effective_xmin;
1286 : :
1287 : : /* check the catalog xmin */
4446 1288 [ + + + + ]: 2474 : if (TransactionIdIsValid(effective_catalog_xmin) &&
1289 [ + + ]: 1046 : (!TransactionIdIsValid(agg_catalog_xmin) ||
1290 : 1046 : TransactionIdPrecedes(effective_catalog_xmin, agg_catalog_xmin)))
1291 : 1275 : agg_catalog_xmin = effective_catalog_xmin;
1292 : : }
1293 : :
1294 : 2612 : ProcArraySetReplicationSlotXmin(agg_xmin, agg_catalog_xmin, already_locked);
1295 : :
126 msawada@postgresql.o 1296 [ + + ]: 2612 : if (!already_locked)
1297 : 2100 : LWLockRelease(ReplicationSlotControlLock);
4477 rhaas@postgresql.org 1298 : 2612 : }
1299 : :
1300 : : /*
1301 : : * Compute the oldest restart LSN across all slots and inform xlog module.
1302 : : *
1303 : : * Note: while max_slot_wal_keep_size is theoretically relevant for this
1304 : : * purpose, we don't try to account for that, because this module doesn't
1305 : : * know what to compare against.
1306 : : */
1307 : : void
1308 : 44642 : ReplicationSlotsComputeRequiredLSN(void)
1309 : : {
1310 : : int i;
4382 bruce@momjian.us 1311 : 44642 : XLogRecPtr min_required = InvalidXLogRecPtr;
1312 : :
4477 rhaas@postgresql.org 1313 [ - + ]: 44642 : Assert(ReplicationSlotCtl != NULL);
1314 : :
1315 : 44642 : LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
28 alvherre@kurilemu.de 1316 [ + + ]:GNC 709813 : for (i = 0; i < max_replication_slots + max_repack_replication_slots; i++)
1317 : : {
4477 rhaas@postgresql.org 1318 :CBC 665171 : ReplicationSlot *s = &ReplicationSlotCtl->replication_slots[i];
1319 : : XLogRecPtr restart_lsn;
1320 : : XLogRecPtr last_saved_restart_lsn;
1321 : : bool invalidated;
1322 : : ReplicationSlotPersistency persistency;
1323 : :
1324 [ + + ]: 665171 : if (!s->in_use)
1325 : 620500 : continue;
1326 : :
3864 1327 [ - + ]: 44671 : SpinLockAcquire(&s->mutex);
325 akorotkov@postgresql 1328 : 44671 : persistency = s->data.persistency;
3864 rhaas@postgresql.org 1329 : 44671 : restart_lsn = s->data.restart_lsn;
1124 andres@anarazel.de 1330 : 44671 : invalidated = s->data.invalidated != RS_INVAL_NONE;
325 akorotkov@postgresql 1331 : 44671 : last_saved_restart_lsn = s->last_saved_restart_lsn;
3864 rhaas@postgresql.org 1332 : 44671 : SpinLockRelease(&s->mutex);
1333 : :
1334 : : /* invalidated slots need not apply */
1124 andres@anarazel.de 1335 [ + + ]: 44671 : if (invalidated)
1336 : 27 : continue;
1337 : :
1338 : : /*
1339 : : * For persistent slot use last_saved_restart_lsn to compute the
1340 : : * oldest LSN for removal of WAL segments. The segments between
1341 : : * last_saved_restart_lsn and restart_lsn might be needed by a
1342 : : * persistent slot in the case of database crash. Non-persistent
1343 : : * slots can't survive the database crash, so we don't care about
1344 : : * last_saved_restart_lsn for them.
1345 : : */
325 akorotkov@postgresql 1346 [ + + ]: 44644 : if (persistency == RS_PERSISTENT)
1347 : : {
180 alvherre@kurilemu.de 1348 [ + + + + ]:GNC 43766 : if (XLogRecPtrIsValid(last_saved_restart_lsn) &&
1349 : : restart_lsn > last_saved_restart_lsn)
1350 : : {
325 akorotkov@postgresql 1351 :CBC 41218 : restart_lsn = last_saved_restart_lsn;
1352 : : }
1353 : : }
1354 : :
180 alvherre@kurilemu.de 1355 [ + + + + ]:GNC 44644 : if (XLogRecPtrIsValid(restart_lsn) &&
1356 [ + + ]: 1202 : (!XLogRecPtrIsValid(min_required) ||
1357 : : restart_lsn < min_required))
4477 rhaas@postgresql.org 1358 :CBC 43510 : min_required = restart_lsn;
1359 : : }
1360 : 44642 : LWLockRelease(ReplicationSlotControlLock);
1361 : :
1362 : 44642 : XLogSetReplicationSlotMinimumLSN(min_required);
1363 : 44642 : }
1364 : :
1365 : : /*
1366 : : * Compute the oldest WAL LSN required by *logical* decoding slots..
1367 : : *
1368 : : * Returns InvalidXLogRecPtr if logical decoding is disabled or no logical
1369 : : * slots exist.
1370 : : *
1371 : : * NB: this returns a value >= ReplicationSlotsComputeRequiredLSN(), since it
1372 : : * ignores physical replication slots.
1373 : : *
1374 : : * The results aren't required frequently, so we don't maintain a precomputed
1375 : : * value like we do for ComputeRequiredLSN() and ComputeRequiredXmin().
1376 : : */
1377 : : XLogRecPtr
4446 1378 : 3888 : ReplicationSlotsComputeLogicalRestartLSN(void)
1379 : : {
1380 : 3888 : XLogRecPtr result = InvalidXLogRecPtr;
1381 : : int i;
1382 : :
28 alvherre@kurilemu.de 1383 [ - + ]:GNC 3888 : if (max_replication_slots + max_repack_replication_slots <= 0)
4446 rhaas@postgresql.org 1384 :UBC 0 : return InvalidXLogRecPtr;
1385 : :
4446 rhaas@postgresql.org 1386 :CBC 3888 : LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
1387 : :
28 alvherre@kurilemu.de 1388 [ + + ]:GNC 61658 : for (i = 0; i < max_replication_slots + max_repack_replication_slots; i++)
1389 : : {
1390 : : ReplicationSlot *s;
1391 : : XLogRecPtr restart_lsn;
1392 : : XLogRecPtr last_saved_restart_lsn;
1393 : : bool invalidated;
1394 : : ReplicationSlotPersistency persistency;
1395 : :
4446 rhaas@postgresql.org 1396 :CBC 57770 : s = &ReplicationSlotCtl->replication_slots[i];
1397 : :
1398 : : /* cannot change while ReplicationSlotCtlLock is held */
1399 [ + + ]: 57770 : if (!s->in_use)
1400 : 56946 : continue;
1401 : :
1402 : : /* we're only interested in logical slots */
3920 andres@anarazel.de 1403 [ + + ]: 824 : if (!SlotIsLogical(s))
4446 rhaas@postgresql.org 1404 : 568 : continue;
1405 : :
1406 : : /* read once, it's ok if it increases while we're checking */
1407 [ - + ]: 256 : SpinLockAcquire(&s->mutex);
325 akorotkov@postgresql 1408 : 256 : persistency = s->data.persistency;
4446 rhaas@postgresql.org 1409 : 256 : restart_lsn = s->data.restart_lsn;
1124 andres@anarazel.de 1410 : 256 : invalidated = s->data.invalidated != RS_INVAL_NONE;
325 akorotkov@postgresql 1411 : 256 : last_saved_restart_lsn = s->last_saved_restart_lsn;
4446 rhaas@postgresql.org 1412 : 256 : SpinLockRelease(&s->mutex);
1413 : :
1414 : : /* invalidated slots need not apply */
1124 andres@anarazel.de 1415 [ + + ]: 256 : if (invalidated)
1416 : 10 : continue;
1417 : :
1418 : : /*
1419 : : * For persistent slot use last_saved_restart_lsn to compute the
1420 : : * oldest LSN for removal of WAL segments. The segments between
1421 : : * last_saved_restart_lsn and restart_lsn might be needed by a
1422 : : * persistent slot in the case of database crash. Non-persistent
1423 : : * slots can't survive the database crash, so we don't care about
1424 : : * last_saved_restart_lsn for them.
1425 : : */
325 akorotkov@postgresql 1426 [ + + ]: 246 : if (persistency == RS_PERSISTENT)
1427 : : {
180 alvherre@kurilemu.de 1428 [ + - - + ]:GNC 244 : if (XLogRecPtrIsValid(last_saved_restart_lsn) &&
1429 : : restart_lsn > last_saved_restart_lsn)
1430 : : {
325 akorotkov@postgresql 1431 :UBC 0 : restart_lsn = last_saved_restart_lsn;
1432 : : }
1433 : : }
1434 : :
180 alvherre@kurilemu.de 1435 [ - + ]:GNC 246 : if (!XLogRecPtrIsValid(restart_lsn))
2219 alvherre@alvh.no-ip. 1436 :UBC 0 : continue;
1437 : :
180 alvherre@kurilemu.de 1438 [ + + + + ]:GNC 246 : if (!XLogRecPtrIsValid(result) ||
1439 : : restart_lsn < result)
4446 rhaas@postgresql.org 1440 :CBC 192 : result = restart_lsn;
1441 : : }
1442 : :
1443 : 3888 : LWLockRelease(ReplicationSlotControlLock);
1444 : :
1445 : 3888 : return result;
1446 : : }
1447 : :
1448 : : /*
1449 : : * ReplicationSlotsCountDBSlots -- count the number of slots that refer to the
1450 : : * passed database oid.
1451 : : *
1452 : : * Returns true if there are any slots referencing the database. *nslots will
1453 : : * be set to the absolute number of slots in the database, *nactive to ones
1454 : : * currently active.
1455 : : */
1456 : : bool
1457 : 51 : ReplicationSlotsCountDBSlots(Oid dboid, int *nslots, int *nactive)
1458 : : {
1459 : : int i;
1460 : :
1461 : 51 : *nslots = *nactive = 0;
1462 : :
28 alvherre@kurilemu.de 1463 [ - + ]:GNC 51 : if (max_replication_slots + max_repack_replication_slots <= 0)
4446 rhaas@postgresql.org 1464 :UBC 0 : return false;
1465 : :
4446 rhaas@postgresql.org 1466 :CBC 51 : LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
28 alvherre@kurilemu.de 1467 [ + + ]:GNC 789 : for (i = 0; i < max_replication_slots + max_repack_replication_slots; i++)
1468 : : {
1469 : : ReplicationSlot *s;
1470 : :
4446 rhaas@postgresql.org 1471 :CBC 738 : s = &ReplicationSlotCtl->replication_slots[i];
1472 : :
1473 : : /* cannot change while ReplicationSlotCtlLock is held */
1474 [ + + ]: 738 : if (!s->in_use)
1475 : 717 : continue;
1476 : :
1477 : : /* only logical slots are database specific, skip */
3920 andres@anarazel.de 1478 [ + + ]: 21 : if (!SlotIsLogical(s))
4442 bruce@momjian.us 1479 : 10 : continue;
1480 : :
1481 : : /* not our database, skip */
4446 rhaas@postgresql.org 1482 [ + + ]: 11 : if (s->data.database != dboid)
1483 : 8 : continue;
1484 : :
1485 : : /* NB: intentionally counting invalidated slots */
1486 : :
1487 : : /* count slots with spinlock held */
1488 [ - + ]: 3 : SpinLockAcquire(&s->mutex);
1489 : 3 : (*nslots)++;
84 heikki.linnakangas@i 1490 [ + + ]:GNC 3 : if (s->active_proc != INVALID_PROC_NUMBER)
4446 rhaas@postgresql.org 1491 :CBC 1 : (*nactive)++;
1492 : 3 : SpinLockRelease(&s->mutex);
1493 : : }
1494 : 51 : LWLockRelease(ReplicationSlotControlLock);
1495 : :
1496 [ + + ]: 51 : if (*nslots > 0)
1497 : 3 : return true;
1498 : 48 : return false;
1499 : : }
1500 : :
1501 : : /*
1502 : : * ReplicationSlotsDropDBSlots -- Drop all db-specific slots relating to the
1503 : : * passed database oid. The caller should hold an exclusive lock on the
1504 : : * pg_database oid for the database to prevent creation of new slots on the db
1505 : : * or replay from existing slots.
1506 : : *
1507 : : * Another session that concurrently acquires an existing slot on the target DB
1508 : : * (most likely to drop it) may cause this function to ERROR. If that happens
1509 : : * it may have dropped some but not all slots.
1510 : : *
1511 : : * This routine isn't as efficient as it could be - but we don't drop
1512 : : * databases often, especially databases with lots of slots.
1513 : : *
1514 : : * If it drops the last logical slot in the cluster, it requests to disable
1515 : : * logical decoding.
1516 : : */
1517 : : void
3325 simon@2ndQuadrant.co 1518 : 64 : ReplicationSlotsDropDBSlots(Oid dboid)
1519 : : {
1520 : : int i;
1521 : : bool found_valid_logicalslot;
133 msawada@postgresql.o 1522 :GNC 64 : bool dropped = false;
1523 : :
28 alvherre@kurilemu.de 1524 [ + - ]: 64 : if (max_replication_slots + max_repack_replication_slots <= 0)
3325 simon@2ndQuadrant.co 1525 :UBC 0 : return;
1526 : :
3325 simon@2ndQuadrant.co 1527 :CBC 64 : restart:
133 msawada@postgresql.o 1528 :GNC 69 : found_valid_logicalslot = false;
3325 simon@2ndQuadrant.co 1529 :CBC 69 : LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
28 alvherre@kurilemu.de 1530 [ + + ]:GNC 992 : for (i = 0; i < max_replication_slots + max_repack_replication_slots; i++)
1531 : : {
1532 : : ReplicationSlot *s;
1533 : : char *slotname;
1534 : : ProcNumber active_proc;
1535 : :
3325 simon@2ndQuadrant.co 1536 :CBC 928 : s = &ReplicationSlotCtl->replication_slots[i];
1537 : :
1538 : : /* cannot change while ReplicationSlotCtlLock is held */
1539 [ + + ]: 928 : if (!s->in_use)
1540 : 900 : continue;
1541 : :
1542 : : /* only logical slots are database specific, skip */
1543 [ + + ]: 28 : if (!SlotIsLogical(s))
1544 : 11 : continue;
1545 : :
1546 : : /*
1547 : : * Check logical slots on other databases too so we can disable
1548 : : * logical decoding only if no slots in the cluster.
1549 : : */
133 msawada@postgresql.o 1550 :GNC 17 : SpinLockAcquire(&s->mutex);
1551 : 17 : found_valid_logicalslot |= (s->data.invalidated == RS_INVAL_NONE);
1552 : 17 : SpinLockRelease(&s->mutex);
1553 : :
1554 : : /* not our database, skip */
3325 simon@2ndQuadrant.co 1555 [ + + ]:CBC 17 : if (s->data.database != dboid)
1556 : 12 : continue;
1557 : :
1558 : : /* NB: intentionally including invalidated slots to drop */
1559 : :
1560 : : /* acquire slot, so ReplicationSlotDropAcquired can be reused */
1561 [ - + ]: 5 : SpinLockAcquire(&s->mutex);
1562 : : /* can't change while ReplicationSlotControlLock is held */
3317 andres@anarazel.de 1563 : 5 : slotname = NameStr(s->data.name);
84 heikki.linnakangas@i 1564 :GNC 5 : active_proc = s->active_proc;
1565 [ + - ]: 5 : if (active_proc == INVALID_PROC_NUMBER)
1566 : : {
3325 simon@2ndQuadrant.co 1567 :CBC 5 : MyReplicationSlot = s;
84 heikki.linnakangas@i 1568 :GNC 5 : s->active_proc = MyProcNumber;
1569 : : }
3325 simon@2ndQuadrant.co 1570 :CBC 5 : SpinLockRelease(&s->mutex);
1571 : :
1572 : : /*
1573 : : * Even though we hold an exclusive lock on the database object a
1574 : : * logical slot for that DB can still be active, e.g. if it's
1575 : : * concurrently being dropped by a backend connected to another DB.
1576 : : *
1577 : : * That's fairly unlikely in practice, so we'll just bail out.
1578 : : *
1579 : : * The slot sync worker holds a shared lock on the database before
1580 : : * operating on synced logical slots to avoid conflict with the drop
1581 : : * happening here. The persistent synced slots are thus safe but there
1582 : : * is a possibility that the slot sync worker has created a temporary
1583 : : * slot (which stays active even on release) and we are trying to drop
1584 : : * that here. In practice, the chances of hitting this scenario are
1585 : : * less as during slot synchronization, the temporary slot is
1586 : : * immediately converted to persistent and thus is safe due to the
1587 : : * shared lock taken on the database. So, we'll just bail out in such
1588 : : * a case.
1589 : : *
1590 : : * XXX: We can consider shutting down the slot sync worker before
1591 : : * trying to drop synced temporary slots here.
1592 : : */
84 heikki.linnakangas@i 1593 [ - + ]:GNC 5 : if (active_proc != INVALID_PROC_NUMBER)
3317 andres@anarazel.de 1594 [ # # ]:UBC 0 : ereport(ERROR,
1595 : : (errcode(ERRCODE_OBJECT_IN_USE),
1596 : : errmsg("replication slot \"%s\" is active for PID %d",
1597 : : slotname, GetPGProcByNumber(active_proc)->pid)));
1598 : :
1599 : : /*
1600 : : * To avoid duplicating ReplicationSlotDropAcquired() and to avoid
1601 : : * holding ReplicationSlotControlLock over filesystem operations,
1602 : : * release ReplicationSlotControlLock and use
1603 : : * ReplicationSlotDropAcquired.
1604 : : *
1605 : : * As that means the set of slots could change, restart scan from the
1606 : : * beginning each time we release the lock.
1607 : : */
3325 simon@2ndQuadrant.co 1608 :CBC 5 : LWLockRelease(ReplicationSlotControlLock);
1609 : 5 : ReplicationSlotDropAcquired();
133 msawada@postgresql.o 1610 :GNC 5 : dropped = true;
3325 simon@2ndQuadrant.co 1611 :CBC 5 : goto restart;
1612 : : }
1613 : 64 : LWLockRelease(ReplicationSlotControlLock);
1614 : :
133 msawada@postgresql.o 1615 [ + + - + ]:GNC 64 : if (dropped && !found_valid_logicalslot)
133 msawada@postgresql.o 1616 :UNC 0 : RequestDisableLogicalDecoding();
1617 : : }
1618 : :
1619 : : /*
1620 : : * Returns true if there is at least one in-use valid logical replication slot.
1621 : : */
1622 : : bool
133 msawada@postgresql.o 1623 :GNC 493 : CheckLogicalSlotExists(void)
1624 : : {
1625 : 493 : bool found = false;
1626 : :
28 alvherre@kurilemu.de 1627 [ - + ]: 493 : if (max_replication_slots + max_repack_replication_slots <= 0)
133 msawada@postgresql.o 1628 :UNC 0 : return false;
1629 : :
133 msawada@postgresql.o 1630 :GNC 493 : LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
28 alvherre@kurilemu.de 1631 [ + + ]: 7764 : for (int i = 0; i < max_replication_slots + max_repack_replication_slots; i++)
1632 : : {
1633 : : ReplicationSlot *s;
1634 : : bool invalidated;
1635 : :
133 msawada@postgresql.o 1636 : 7277 : s = &ReplicationSlotCtl->replication_slots[i];
1637 : :
1638 : : /* cannot change while ReplicationSlotCtlLock is held */
1639 [ + + ]: 7277 : if (!s->in_use)
1640 : 7249 : continue;
1641 : :
1642 [ + + ]: 28 : if (SlotIsPhysical(s))
1643 : 19 : continue;
1644 : :
1645 : 9 : SpinLockAcquire(&s->mutex);
1646 : 9 : invalidated = s->data.invalidated != RS_INVAL_NONE;
1647 : 9 : SpinLockRelease(&s->mutex);
1648 : :
1649 [ + + ]: 9 : if (invalidated)
1650 : 3 : continue;
1651 : :
1652 : 6 : found = true;
1653 : 6 : break;
1654 : : }
1655 : 493 : LWLockRelease(ReplicationSlotControlLock);
1656 : :
1657 : 493 : return found;
1658 : : }
1659 : :
1660 : : /*
1661 : : * Check whether the server's configuration supports using replication
1662 : : * slots.
1663 : : */
1664 : : void
28 alvherre@kurilemu.de 1665 : 1883 : CheckSlotRequirements(bool repack)
1666 : : {
1667 : : /*
1668 : : * NB: Adding a new requirement likely means that RestoreSlotFromDisk()
1669 : : * needs the same check.
1670 : : */
1671 : :
1672 [ + + - + ]: 1883 : if (!repack && max_replication_slots == 0)
4477 rhaas@postgresql.org 1673 [ # # ]:UBC 0 : ereport(ERROR,
1674 : : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1675 : : errmsg("replication slots can only be used if \"%s\" > 0",
1676 : : "max_replication_slots"));
1677 : :
28 alvherre@kurilemu.de 1678 [ + + - + ]:GNC 1883 : if (repack && max_repack_replication_slots == 0)
28 alvherre@kurilemu.de 1679 [ # # ]:UNC 0 : ereport(ERROR,
1680 : : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1681 : : errmsg("REPACK can only be used if \"%s\" > 0",
1682 : : "max_repack_replication_slots"));
1683 : :
3718 peter_e@gmx.net 1684 [ - + ]:CBC 1883 : if (wal_level < WAL_LEVEL_REPLICA)
4477 rhaas@postgresql.org 1685 [ # # ]:UBC 0 : ereport(ERROR,
1686 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
1687 : : errmsg("replication slots can only be used if \"wal_level\" >= \"replica\"")));
4477 rhaas@postgresql.org 1688 :CBC 1883 : }
1689 : :
1690 : : /*
1691 : : * Check whether the user has privilege to use replication slots.
1692 : : */
1693 : : void
1694 michael@paquier.xyz 1694 : 599 : CheckSlotPermissions(void)
1695 : : {
1146 peter@eisentraut.org 1696 [ + + ]: 599 : if (!has_rolreplication(GetUserId()))
1694 michael@paquier.xyz 1697 [ + - ]: 5 : ereport(ERROR,
1698 : : (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
1699 : : errmsg("permission denied to use replication slots"),
1700 : : errdetail("Only roles with the %s attribute may use replication slots.",
1701 : : "REPLICATION")));
1702 : 594 : }
1703 : :
1704 : : /*
1705 : : * Reserve WAL for the currently active slot.
1706 : : *
1707 : : * Compute and set restart_lsn in a manner that's appropriate for the type of
1708 : : * the slot and concurrency safe.
1709 : : */
1710 : : void
3920 andres@anarazel.de 1711 : 658 : ReplicationSlotReserveWal(void)
1712 : : {
1713 : 658 : ReplicationSlot *slot = MyReplicationSlot;
1714 : : XLogSegNo segno;
1715 : : XLogRecPtr restart_lsn;
1716 : :
1717 [ - + ]: 658 : Assert(slot != NULL);
180 alvherre@kurilemu.de 1718 [ - + ]:GNC 658 : Assert(!XLogRecPtrIsValid(slot->data.restart_lsn));
1719 [ - + ]: 658 : Assert(!XLogRecPtrIsValid(slot->last_saved_restart_lsn));
1720 : :
1721 : : /*
1722 : : * The replication slot mechanism is used to prevent the removal of
1723 : : * required WAL.
1724 : : *
1725 : : * Acquire an exclusive lock to prevent the checkpoint process from
1726 : : * concurrently computing the minimum slot LSN (see
1727 : : * CheckPointReplicationSlots). This ensures that the WAL reserved for
1728 : : * replication cannot be removed during a checkpoint.
1729 : : *
1730 : : * The mechanism is reliable because if WAL reservation occurs first, the
1731 : : * checkpoint must wait for the restart_lsn update before determining the
1732 : : * minimum non-removable LSN. On the other hand, if the checkpoint happens
1733 : : * first, subsequent WAL reservations will select positions at or beyond
1734 : : * the redo pointer of that checkpoint.
1735 : : */
148 akapila@postgresql.o 1736 :CBC 658 : LWLockAcquire(ReplicationSlotAllocationLock, LW_EXCLUSIVE);
1737 : :
1738 : : /*
1739 : : * For logical slots log a standby snapshot and start logical decoding at
1740 : : * exactly that position. That allows the slot to start up more quickly.
1741 : : * But on a standby we cannot do WAL writes, so just use the replay
1742 : : * pointer; effectively, an attempt to create a logical slot on standby
1743 : : * will cause it to wait for an xl_running_xact record to be logged
1744 : : * independently on the primary, so that a snapshot can be built using the
1745 : : * record.
1746 : : *
1747 : : * None of this is needed (or indeed helpful) for physical slots as
1748 : : * they'll start replay at the last logged checkpoint anyway. Instead,
1749 : : * return the location of the last redo LSN, where a base backup has to
1750 : : * start replay at.
1751 : : */
1752 [ + + ]: 658 : if (SlotIsPhysical(slot))
1753 : 166 : restart_lsn = GetRedoRecPtr();
1754 [ + + ]: 492 : else if (RecoveryInProgress())
1755 : 26 : restart_lsn = GetXLogReplayRecPtr(NULL);
1756 : : else
1757 : 466 : restart_lsn = GetXLogInsertRecPtr();
1758 : :
1759 [ - + ]: 658 : SpinLockAcquire(&slot->mutex);
1760 : 658 : slot->data.restart_lsn = restart_lsn;
1761 : 658 : SpinLockRelease(&slot->mutex);
1762 : :
1763 : : /* prevent WAL removal as fast as possible */
1764 : 658 : ReplicationSlotsComputeRequiredLSN();
1765 : :
1766 : : /* Checkpoint shouldn't remove the required WAL. */
1767 : 658 : XLByteToSeg(slot->data.restart_lsn, segno, wal_segment_size);
1768 [ - + ]: 658 : if (XLogGetLastRemovedSegno() >= segno)
148 akapila@postgresql.o 1769 [ # # ]:UBC 0 : elog(ERROR, "WAL required by replication slot %s has been removed concurrently",
1770 : : NameStr(slot->data.name));
1771 : :
148 akapila@postgresql.o 1772 :CBC 658 : LWLockRelease(ReplicationSlotAllocationLock);
1773 : :
1123 andres@anarazel.de 1774 [ + + + + ]: 658 : if (!RecoveryInProgress() && SlotIsLogical(slot))
1775 : : {
1776 : : XLogRecPtr flushptr;
1777 : :
1778 : : /* make sure we have enough information to start */
28 alvherre@kurilemu.de 1779 :GNC 466 : flushptr = LogStandbySnapshot(InvalidOid);
1780 : :
1781 : : /* and make sure it's fsynced to disk */
1123 andres@anarazel.de 1782 :CBC 466 : XLogFlush(flushptr);
1783 : : }
3920 1784 : 658 : }
1785 : :
1786 : : /*
1787 : : * Report that replication slot needs to be invalidated
1788 : : */
1789 : : static void
1124 1790 : 23 : ReportSlotInvalidation(ReplicationSlotInvalidationCause cause,
1791 : : bool terminating,
1792 : : int pid,
1793 : : NameData slotname,
1794 : : XLogRecPtr restart_lsn,
1795 : : XLogRecPtr oldestLSN,
1796 : : TransactionId snapshotConflictHorizon,
1797 : : long slot_idle_seconds)
1798 : : {
1799 : : StringInfoData err_detail;
1800 : : StringInfoData err_hint;
1801 : :
1802 : 23 : initStringInfo(&err_detail);
440 akapila@postgresql.o 1803 : 23 : initStringInfo(&err_hint);
1804 : :
1124 andres@anarazel.de 1805 [ + + + - : 23 : switch (cause)
- - ]
1806 : : {
1807 : 7 : case RS_INVAL_WAL_REMOVED:
1808 : : {
402 peter@eisentraut.org 1809 : 7 : uint64 ex = oldestLSN - restart_lsn;
1810 : :
985 1811 : 7 : appendStringInfo(&err_detail,
302 alvherre@kurilemu.de 1812 :GNC 7 : ngettext("The slot's restart_lsn %X/%08X exceeds the limit by %" PRIu64 " byte.",
1813 : : "The slot's restart_lsn %X/%08X exceeds the limit by %" PRIu64 " bytes.",
1814 : : ex),
985 peter@eisentraut.org 1815 :CBC 7 : LSN_FORMAT_ARGS(restart_lsn),
1816 : : ex);
1817 : : /* translator: %s is a GUC variable name */
440 akapila@postgresql.o 1818 : 7 : appendStringInfo(&err_hint, _("You might need to increase \"%s\"."),
1819 : : "max_slot_wal_keep_size");
985 peter@eisentraut.org 1820 : 7 : break;
1821 : : }
1124 andres@anarazel.de 1822 : 12 : case RS_INVAL_HORIZON:
1823 : 12 : appendStringInfo(&err_detail, _("The slot conflicted with xid horizon %u."),
1824 : : snapshotConflictHorizon);
1825 : 12 : break;
1826 : :
1827 : 4 : case RS_INVAL_WAL_LEVEL:
133 msawada@postgresql.o 1828 :GNC 4 : appendStringInfoString(&err_detail, _("Logical decoding on standby requires the primary server to either set \"wal_level\" >= \"logical\" or have at least one logical slot when \"wal_level\" = \"replica\"."));
1124 andres@anarazel.de 1829 :CBC 4 : break;
1830 : :
440 akapila@postgresql.o 1831 :UBC 0 : case RS_INVAL_IDLE_TIMEOUT:
1832 : : {
1833 : : /* translator: %s is a GUC variable name */
298 fujii@postgresql.org 1834 : 0 : appendStringInfo(&err_detail, _("The slot's idle time of %lds exceeds the configured \"%s\" duration of %ds."),
1835 : : slot_idle_seconds, "idle_replication_slot_timeout",
1836 : : idle_replication_slot_timeout_secs);
1837 : : /* translator: %s is a GUC variable name */
440 akapila@postgresql.o 1838 : 0 : appendStringInfo(&err_hint, _("You might need to increase \"%s\"."),
1839 : : "idle_replication_slot_timeout");
1840 : 0 : break;
1841 : : }
1124 andres@anarazel.de 1842 : 0 : case RS_INVAL_NONE:
1843 : 0 : pg_unreachable();
1844 : : }
1845 : :
1124 andres@anarazel.de 1846 [ + - + + :CBC 23 : ereport(LOG,
+ + ]
1847 : : terminating ?
1848 : : errmsg("terminating process %d to release replication slot \"%s\"",
1849 : : pid, NameStr(slotname)) :
1850 : : errmsg("invalidating obsolete replication slot \"%s\"",
1851 : : NameStr(slotname)),
1852 : : errdetail_internal("%s", err_detail.data),
1853 : : err_hint.len ? errhint("%s", err_hint.data) : 0);
1854 : :
1855 : 23 : pfree(err_detail.data);
440 akapila@postgresql.o 1856 : 23 : pfree(err_hint.data);
1857 : 23 : }
1858 : :
1859 : : /*
1860 : : * Can we invalidate an idle replication slot?
1861 : : *
1862 : : * Idle timeout invalidation is allowed only when:
1863 : : *
1864 : : * 1. Idle timeout is set
1865 : : * 2. Slot has reserved WAL
1866 : : * 3. Slot is inactive
1867 : : * 4. The slot is not being synced from the primary while the server is in
1868 : : * recovery. This is because synced slots are always considered to be
1869 : : * inactive because they don't perform logical decoding to produce changes.
1870 : : */
1871 : : static inline bool
1872 : 389 : CanInvalidateIdleSlot(ReplicationSlot *s)
1873 : : {
298 fujii@postgresql.org 1874 : 389 : return (idle_replication_slot_timeout_secs != 0 &&
180 alvherre@kurilemu.de 1875 [ # # ]:UNC 0 : XLogRecPtrIsValid(s->data.restart_lsn) &&
440 akapila@postgresql.o 1876 [ - + - - ]:CBC 389 : s->inactive_since > 0 &&
440 akapila@postgresql.o 1877 [ # # # # ]:UBC 0 : !(RecoveryInProgress() && s->data.synced));
1878 : : }
1879 : :
1880 : : /*
1881 : : * DetermineSlotInvalidationCause - Determine the cause for which a slot
1882 : : * becomes invalid among the given possible causes.
1883 : : *
1884 : : * This function sequentially checks all possible invalidation causes and
1885 : : * returns the first one for which the slot is eligible for invalidation.
1886 : : */
1887 : : static ReplicationSlotInvalidationCause
440 akapila@postgresql.o 1888 :CBC 422 : DetermineSlotInvalidationCause(uint32 possible_causes, ReplicationSlot *s,
1889 : : XLogRecPtr oldestLSN, Oid dboid,
1890 : : TransactionId snapshotConflictHorizon,
1891 : : TimestampTz *inactive_since, TimestampTz now)
1892 : : {
1893 [ - + ]: 422 : Assert(possible_causes != RS_INVAL_NONE);
1894 : :
1895 [ + + ]: 422 : if (possible_causes & RS_INVAL_WAL_REMOVED)
1896 : : {
187 michael@paquier.xyz 1897 : 396 : XLogRecPtr restart_lsn = s->data.restart_lsn;
1898 : :
180 alvherre@kurilemu.de 1899 [ + + + + ]:GNC 396 : if (XLogRecPtrIsValid(restart_lsn) &&
1900 : : restart_lsn < oldestLSN)
440 akapila@postgresql.o 1901 :CBC 7 : return RS_INVAL_WAL_REMOVED;
1902 : : }
1903 : :
1904 [ + + ]: 415 : if (possible_causes & RS_INVAL_HORIZON)
1905 : : {
1906 : : /* invalid DB oid signals a shared relation */
1907 [ + - + + ]: 22 : if (SlotIsLogical(s) &&
1908 [ + - ]: 17 : (dboid == InvalidOid || dboid == s->data.database))
1909 : : {
187 michael@paquier.xyz 1910 : 22 : TransactionId effective_xmin = s->effective_xmin;
1911 : 22 : TransactionId catalog_effective_xmin = s->effective_catalog_xmin;
1912 : :
1913 [ - + - - ]: 22 : if (TransactionIdIsValid(effective_xmin) &&
187 michael@paquier.xyz 1914 :UBC 0 : TransactionIdPrecedesOrEquals(effective_xmin,
1915 : : snapshotConflictHorizon))
440 akapila@postgresql.o 1916 : 0 : return RS_INVAL_HORIZON;
187 michael@paquier.xyz 1917 [ + - + + ]:CBC 44 : else if (TransactionIdIsValid(catalog_effective_xmin) &&
1918 : 22 : TransactionIdPrecedesOrEquals(catalog_effective_xmin,
1919 : : snapshotConflictHorizon))
440 akapila@postgresql.o 1920 : 12 : return RS_INVAL_HORIZON;
1921 : : }
1922 : : }
1923 : :
1924 [ + + ]: 403 : if (possible_causes & RS_INVAL_WAL_LEVEL)
1925 : : {
1926 [ + - ]: 4 : if (SlotIsLogical(s))
1927 : 4 : return RS_INVAL_WAL_LEVEL;
1928 : : }
1929 : :
1930 [ + + ]: 399 : if (possible_causes & RS_INVAL_IDLE_TIMEOUT)
1931 : : {
1932 [ - + ]: 389 : Assert(now > 0);
1933 : :
1934 [ - + ]: 389 : if (CanInvalidateIdleSlot(s))
1935 : : {
1936 : : /*
1937 : : * Simulate the invalidation due to idle_timeout to test the
1938 : : * timeout behavior promptly, without waiting for it to trigger
1939 : : * naturally.
1940 : : */
1941 : : #ifdef USE_INJECTION_POINTS
440 akapila@postgresql.o 1942 [ # # ]:UBC 0 : if (IS_INJECTION_POINT_ATTACHED("slot-timeout-inval"))
1943 : : {
1944 : 0 : *inactive_since = 0; /* since the beginning of time */
1945 : 0 : return RS_INVAL_IDLE_TIMEOUT;
1946 : : }
1947 : : #endif
1948 : :
1949 : : /*
1950 : : * Check if the slot needs to be invalidated due to
1951 : : * idle_replication_slot_timeout GUC.
1952 : : */
1953 [ # # ]: 0 : if (TimestampDifferenceExceedsSeconds(s->inactive_since, now,
1954 : : idle_replication_slot_timeout_secs))
1955 : : {
1956 : 0 : *inactive_since = s->inactive_since;
1957 : 0 : return RS_INVAL_IDLE_TIMEOUT;
1958 : : }
1959 : : }
1960 : : }
1961 : :
440 akapila@postgresql.o 1962 :CBC 399 : return RS_INVAL_NONE;
1963 : : }
1964 : :
1965 : : /*
1966 : : * Helper for InvalidateObsoleteReplicationSlots
1967 : : *
1968 : : * Acquires the given slot and mark it invalid, if necessary and possible.
1969 : : *
1970 : : * Returns true if the slot was invalidated.
1971 : : *
1972 : : * Set *released_lock_out if ReplicationSlotControlLock was released in the
1973 : : * interim (and in that case we're not holding the lock at return, otherwise
1974 : : * we are).
1975 : : *
1976 : : * This is inherently racy, because we release the LWLock
1977 : : * for syscalls, so caller must restart if we return true.
1978 : : */
1979 : : static bool
1980 : 461 : InvalidatePossiblyObsoleteSlot(uint32 possible_causes,
1981 : : ReplicationSlot *s,
1982 : : XLogRecPtr oldestLSN,
1983 : : Oid dboid, TransactionId snapshotConflictHorizon,
1984 : : bool *released_lock_out)
1985 : : {
1789 alvherre@alvh.no-ip. 1986 : 461 : int last_signaled_pid = 0;
1987 : 461 : bool released_lock = false;
133 msawada@postgresql.o 1988 :GNC 461 : bool invalidated = false;
440 akapila@postgresql.o 1989 :CBC 461 : TimestampTz inactive_since = 0;
1990 : :
1991 : : for (;;)
2219 alvherre@alvh.no-ip. 1992 : 7 : {
1993 : : XLogRecPtr restart_lsn;
1994 : : NameData slotname;
1995 : : ProcNumber active_proc;
1789 1996 : 468 : int active_pid = 0;
774 akapila@postgresql.o 1997 : 468 : ReplicationSlotInvalidationCause invalidation_cause = RS_INVAL_NONE;
440 1998 : 468 : TimestampTz now = 0;
1999 : 468 : long slot_idle_secs = 0;
2000 : :
1789 alvherre@alvh.no-ip. 2001 [ - + ]: 468 : Assert(LWLockHeldByMeInMode(ReplicationSlotControlLock, LW_SHARED));
2002 : :
2219 2003 [ - + ]: 468 : if (!s->in_use)
2004 : : {
1789 alvherre@alvh.no-ip. 2005 [ # # ]:UBC 0 : if (released_lock)
2006 : 0 : LWLockRelease(ReplicationSlotControlLock);
2007 : 0 : break;
2008 : : }
2009 : :
440 akapila@postgresql.o 2010 [ + + ]:CBC 468 : if (possible_causes & RS_INVAL_IDLE_TIMEOUT)
2011 : : {
2012 : : /*
2013 : : * Assign the current time here to avoid system call overhead
2014 : : * while holding the spinlock in subsequent code.
2015 : : */
2016 : 410 : now = GetCurrentTimestamp();
2017 : : }
2018 : :
2019 : : /*
2020 : : * Check if the slot needs to be invalidated. If it needs to be
2021 : : * invalidated, and is not currently acquired, acquire it and mark it
2022 : : * as having been invalidated. We do this with the spinlock held to
2023 : : * avoid race conditions -- for example the restart_lsn could move
2024 : : * forward, or the slot could be dropped.
2025 : : */
2219 alvherre@alvh.no-ip. 2026 [ - + ]: 468 : SpinLockAcquire(&s->mutex);
2027 : :
2028 : 468 : restart_lsn = s->data.restart_lsn;
2029 : :
2030 : : /* we do nothing if the slot is already invalid */
1124 andres@anarazel.de 2031 [ + + ]: 468 : if (s->data.invalidated == RS_INVAL_NONE)
440 akapila@postgresql.o 2032 : 422 : invalidation_cause = DetermineSlotInvalidationCause(possible_causes,
2033 : : s, oldestLSN,
2034 : : dboid,
2035 : : snapshotConflictHorizon,
2036 : : &inactive_since,
2037 : : now);
2038 : :
2039 : : /* if there's no invalidation, we're done */
774 2040 [ + + ]: 468 : if (invalidation_cause == RS_INVAL_NONE)
2041 : : {
1789 alvherre@alvh.no-ip. 2042 : 445 : SpinLockRelease(&s->mutex);
2043 [ - + ]: 445 : if (released_lock)
1789 alvherre@alvh.no-ip. 2044 :UBC 0 : LWLockRelease(ReplicationSlotControlLock);
1789 alvherre@alvh.no-ip. 2045 :CBC 445 : break;
2046 : : }
2047 : :
2048 : 23 : slotname = s->data.name;
84 heikki.linnakangas@i 2049 :GNC 23 : active_proc = s->active_proc;
2050 : :
2051 : : /*
2052 : : * If the slot can be acquired, do so and mark it invalidated
2053 : : * immediately. Otherwise we'll signal the owning process, below, and
2054 : : * retry.
2055 : : *
2056 : : * Note: Unlike other slot attributes, slot's inactive_since can't be
2057 : : * changed until the acquired slot is released or the owning process
2058 : : * is terminated. So, the inactive slot can only be invalidated
2059 : : * immediately without being terminated.
2060 : : */
2061 [ + + ]: 23 : if (active_proc == INVALID_PROC_NUMBER)
2062 : : {
1789 alvherre@alvh.no-ip. 2063 :CBC 16 : MyReplicationSlot = s;
84 heikki.linnakangas@i 2064 :GNC 16 : s->active_proc = MyProcNumber;
774 akapila@postgresql.o 2065 :CBC 16 : s->data.invalidated = invalidation_cause;
2066 : :
2067 : : /*
2068 : : * XXX: We should consider not overwriting restart_lsn and instead
2069 : : * just rely on .invalidated.
2070 : : */
2071 [ + + ]: 16 : if (invalidation_cause == RS_INVAL_WAL_REMOVED)
2072 : : {
1124 andres@anarazel.de 2073 : 5 : s->data.restart_lsn = InvalidXLogRecPtr;
325 akorotkov@postgresql 2074 : 5 : s->last_saved_restart_lsn = InvalidXLogRecPtr;
2075 : : }
2076 : :
2077 : : /* Let caller know */
133 msawada@postgresql.o 2078 :GNC 16 : invalidated = true;
2079 : : }
2080 : : else
2081 : : {
84 heikki.linnakangas@i 2082 : 7 : active_pid = GetPGProcByNumber(active_proc)->pid;
2083 [ - + ]: 7 : Assert(active_pid != 0);
2084 : : }
2085 : :
1789 alvherre@alvh.no-ip. 2086 :CBC 23 : SpinLockRelease(&s->mutex);
2087 : :
2088 : : /*
2089 : : * Calculate the idle time duration of the slot if slot is marked
2090 : : * invalidated with RS_INVAL_IDLE_TIMEOUT.
2091 : : */
440 akapila@postgresql.o 2092 [ - + ]: 23 : if (invalidation_cause == RS_INVAL_IDLE_TIMEOUT)
2093 : : {
2094 : : int slot_idle_usecs;
2095 : :
440 akapila@postgresql.o 2096 :UBC 0 : TimestampDifference(inactive_since, now, &slot_idle_secs,
2097 : : &slot_idle_usecs);
2098 : : }
2099 : :
84 heikki.linnakangas@i 2100 [ + + ]:GNC 23 : if (active_proc != INVALID_PROC_NUMBER)
2101 : : {
2102 : : /*
2103 : : * Prepare the sleep on the slot's condition variable before
2104 : : * releasing the lock, to close a possible race condition if the
2105 : : * slot is released before the sleep below.
2106 : : */
1789 alvherre@alvh.no-ip. 2107 :CBC 7 : ConditionVariablePrepareToSleep(&s->active_cv);
2108 : :
2109 : 7 : LWLockRelease(ReplicationSlotControlLock);
2110 : 7 : released_lock = true;
2111 : :
2112 : : /*
2113 : : * Signal to terminate the process that owns the slot, if we
2114 : : * haven't already signalled it. (Avoidance of repeated
2115 : : * signalling is the only reason for there to be a loop in this
2116 : : * routine; otherwise we could rely on caller's restart loop.)
2117 : : *
2118 : : * There is the race condition that other process may own the slot
2119 : : * after its current owner process is terminated and before this
2120 : : * process owns it. To handle that, we signal only if the PID of
2121 : : * the owning process has changed from the previous time. (This
2122 : : * logic assumes that the same PID is not reused very quickly.)
2123 : : */
2124 [ + - ]: 7 : if (last_signaled_pid != active_pid)
2125 : : {
774 akapila@postgresql.o 2126 : 7 : ReportSlotInvalidation(invalidation_cause, true, active_pid,
2127 : : slotname, restart_lsn,
2128 : : oldestLSN, snapshotConflictHorizon,
2129 : : slot_idle_secs);
2130 : :
1124 andres@anarazel.de 2131 [ + + ]: 7 : if (MyBackendType == B_STARTUP)
84 heikki.linnakangas@i 2132 :GNC 5 : (void) SignalRecoveryConflict(GetPGProcByNumber(active_proc),
2133 : : active_pid,
2134 : : RECOVERY_CONFLICT_LOGICALSLOT);
2135 : : else
1124 andres@anarazel.de 2136 :CBC 2 : (void) kill(active_pid, SIGTERM);
2137 : :
1789 alvherre@alvh.no-ip. 2138 : 7 : last_signaled_pid = active_pid;
2139 : : }
2140 : :
2141 : : /* Wait until the slot is released. */
2142 : 7 : ConditionVariableSleep(&s->active_cv,
2143 : : WAIT_EVENT_REPLICATION_SLOT_DROP);
2144 : :
2145 : : /*
2146 : : * Re-acquire lock and start over; we expect to invalidate the
2147 : : * slot next time (unless another process acquires the slot in the
2148 : : * meantime).
2149 : : *
2150 : : * Note: It is possible for a slot to advance its restart_lsn or
2151 : : * xmin values sufficiently between when we release the mutex and
2152 : : * when we recheck, moving from a conflicting state to a non
2153 : : * conflicting state. This is intentional and safe: if the slot
2154 : : * has caught up while we're busy here, the resources we were
2155 : : * concerned about (WAL segments or tuples) have not yet been
2156 : : * removed, and there's no reason to invalidate the slot.
2157 : : */
2158 : 7 : LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
2159 : 7 : continue;
2160 : : }
2161 : : else
2162 : : {
2163 : : /*
2164 : : * We hold the slot now and have already invalidated it; flush it
2165 : : * to ensure that state persists.
2166 : : *
2167 : : * Don't want to hold ReplicationSlotControlLock across file
2168 : : * system operations, so release it now but be sure to tell caller
2169 : : * to restart from scratch.
2170 : : */
2171 : 16 : LWLockRelease(ReplicationSlotControlLock);
2172 : 16 : released_lock = true;
2173 : :
2174 : : /* Make sure the invalidated state persists across server restart */
2175 : 16 : ReplicationSlotMarkDirty();
2176 : 16 : ReplicationSlotSave();
2177 : 16 : ReplicationSlotRelease();
2178 : :
774 akapila@postgresql.o 2179 : 16 : ReportSlotInvalidation(invalidation_cause, false, active_pid,
2180 : : slotname, restart_lsn,
2181 : : oldestLSN, snapshotConflictHorizon,
2182 : : slot_idle_secs);
2183 : :
2184 : : /* done with this slot for now */
1789 alvherre@alvh.no-ip. 2185 : 16 : break;
2186 : : }
2187 : : }
2188 : :
2189 [ - + ]: 461 : Assert(released_lock == !LWLockHeldByMe(ReplicationSlotControlLock));
2190 : :
133 msawada@postgresql.o 2191 :GNC 461 : *released_lock_out = released_lock;
2192 : 461 : return invalidated;
2193 : : }
2194 : :
2195 : : /*
2196 : : * Invalidate slots that require resources about to be removed.
2197 : : *
2198 : : * Returns true when any slot have got invalidated.
2199 : : *
2200 : : * Whether a slot needs to be invalidated depends on the invalidation cause.
2201 : : * A slot is invalidated if it:
2202 : : * - RS_INVAL_WAL_REMOVED: requires a LSN older than the given segment
2203 : : * - RS_INVAL_HORIZON: requires a snapshot <= the given horizon in the given
2204 : : * db; dboid may be InvalidOid for shared relations
2205 : : * - RS_INVAL_WAL_LEVEL: is a logical slot and effective_wal_level is not
2206 : : * logical.
2207 : : * - RS_INVAL_IDLE_TIMEOUT: has been idle longer than the configured
2208 : : * "idle_replication_slot_timeout" duration.
2209 : : *
2210 : : * Note: This function attempts to invalidate the slot for multiple possible
2211 : : * causes in a single pass, minimizing redundant iterations. The "cause"
2212 : : * parameter can be a MASK representing one or more of the defined causes.
2213 : : *
2214 : : * If it invalidates the last logical slot in the cluster, it requests to
2215 : : * disable logical decoding.
2216 : : *
2217 : : * NB - this runs as part of checkpoint, so avoid raising errors if possible.
2218 : : */
2219 : : bool
440 akapila@postgresql.o 2220 :CBC 1969 : InvalidateObsoleteReplicationSlots(uint32 possible_causes,
2221 : : XLogSegNo oldestSegno, Oid dboid,
2222 : : TransactionId snapshotConflictHorizon)
2223 : : {
2224 : : XLogRecPtr oldestLSN;
1754 alvherre@alvh.no-ip. 2225 : 1969 : bool invalidated = false;
133 msawada@postgresql.o 2226 :GNC 1969 : bool invalidated_logical = false;
2227 : : bool found_valid_logicalslot;
2228 : :
440 akapila@postgresql.o 2229 [ + + - + ]:CBC 1969 : Assert(!(possible_causes & RS_INVAL_HORIZON) || TransactionIdIsValid(snapshotConflictHorizon));
2230 [ + + - + ]: 1969 : Assert(!(possible_causes & RS_INVAL_WAL_REMOVED) || oldestSegno > 0);
2231 [ - + ]: 1969 : Assert(possible_causes != RS_INVAL_NONE);
2232 : :
28 alvherre@kurilemu.de 2233 [ + + - + ]:GNC 1969 : if (max_replication_slots == 0 && max_repack_replication_slots == 0)
1124 andres@anarazel.de 2234 :UBC 0 : return invalidated;
2235 : :
1789 alvherre@alvh.no-ip. 2236 :CBC 1969 : XLogSegNoOffsetToRecPtr(oldestSegno, 0, wal_segment_size, oldestLSN);
2237 : :
2238 : 1985 : restart:
133 msawada@postgresql.o 2239 :GNC 1985 : found_valid_logicalslot = false;
1789 alvherre@alvh.no-ip. 2240 :CBC 1985 : LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
28 alvherre@kurilemu.de 2241 [ + + ]:GNC 31165 : for (int i = 0; i < max_replication_slots + max_repack_replication_slots; i++)
2242 : : {
1789 alvherre@alvh.no-ip. 2243 :CBC 29196 : ReplicationSlot *s = &ReplicationSlotCtl->replication_slots[i];
133 msawada@postgresql.o 2244 :GNC 29196 : bool released_lock = false;
2245 : :
1789 alvherre@alvh.no-ip. 2246 [ + + ]:CBC 29196 : if (!s->in_use)
2247 : 28735 : continue;
2248 : :
2249 : : /* Prevent invalidation of logical slots during binary upgrade */
298 akapila@postgresql.o 2250 [ + + + + ]: 470 : if (SlotIsLogical(s) && IsBinaryUpgrade)
2251 : : {
133 msawada@postgresql.o 2252 :GNC 9 : SpinLockAcquire(&s->mutex);
2253 : 9 : found_valid_logicalslot |= (s->data.invalidated == RS_INVAL_NONE);
2254 : 9 : SpinLockRelease(&s->mutex);
2255 : :
298 akapila@postgresql.o 2256 :CBC 9 : continue;
2257 : : }
2258 : :
133 msawada@postgresql.o 2259 [ + + ]:GNC 461 : if (InvalidatePossiblyObsoleteSlot(possible_causes, s, oldestLSN,
2260 : : dboid, snapshotConflictHorizon,
2261 : : &released_lock))
2262 : : {
2263 [ - + ]: 16 : Assert(released_lock);
2264 : :
2265 : : /* Remember we have invalidated a physical or logical slot */
2266 : 16 : invalidated = true;
2267 : :
2268 : : /*
2269 : : * Additionally, remember we have invalidated a logical slot as we
2270 : : * can request disabling logical decoding later.
2271 : : */
2272 [ + + ]: 16 : if (SlotIsLogical(s))
2273 : 13 : invalidated_logical = true;
2274 : : }
2275 : : else
2276 : : {
2277 : : /*
2278 : : * We need to check if the slot is invalidated here since
2279 : : * InvalidatePossiblyObsoleteSlot() returns false also if the slot
2280 : : * is already invalidated.
2281 : : */
2282 : 445 : SpinLockAcquire(&s->mutex);
2283 : 890 : found_valid_logicalslot |=
2284 [ + + + + ]: 445 : (SlotIsLogical(s) && (s->data.invalidated == RS_INVAL_NONE));
2285 : 445 : SpinLockRelease(&s->mutex);
2286 : : }
2287 : :
2288 : : /* if the lock was released, start from scratch */
2289 [ + + ]: 461 : if (released_lock)
2290 : 16 : goto restart;
2291 : : }
2219 alvherre@alvh.no-ip. 2292 :CBC 1969 : LWLockRelease(ReplicationSlotControlLock);
2293 : :
2294 : : /*
2295 : : * If any slots have been invalidated, recalculate the resource limits.
2296 : : */
1754 2297 [ + + ]: 1969 : if (invalidated)
2298 : : {
2299 : 11 : ReplicationSlotsComputeRequiredXmin(false);
2300 : 11 : ReplicationSlotsComputeRequiredLSN();
2301 : : }
2302 : :
2303 : : /*
2304 : : * Request the checkpointer to disable logical decoding if no valid
2305 : : * logical slots remain. If called by the checkpointer during a
2306 : : * checkpoint, only the request is initiated; actual deactivation is
2307 : : * deferred until after the checkpoint completes.
2308 : : */
133 msawada@postgresql.o 2309 [ + + + - ]:GNC 1969 : if (invalidated_logical && !found_valid_logicalslot)
2310 : 8 : RequestDisableLogicalDecoding();
2311 : :
1754 alvherre@alvh.no-ip. 2312 :CBC 1969 : return invalidated;
2313 : : }
2314 : :
2315 : : /*
2316 : : * Flush all replication slots to disk.
2317 : : *
2318 : : * It is convenient to flush dirty replication slots at the time of checkpoint.
2319 : : * Additionally, in case of a shutdown checkpoint, we also identify the slots
2320 : : * for which the confirmed_flush LSN has been updated since the last time it
2321 : : * was saved and flush them.
2322 : : */
2323 : : void
964 akapila@postgresql.o 2324 : 1944 : CheckPointReplicationSlots(bool is_shutdown)
2325 : : {
2326 : : int i;
312 akorotkov@postgresql 2327 : 1944 : bool last_saved_restart_lsn_updated = false;
2328 : :
4193 peter_e@gmx.net 2329 [ + + ]: 1944 : elog(DEBUG1, "performing replication slot checkpoint");
2330 : :
2331 : : /*
2332 : : * Prevent any slot from being created/dropped while we're active. As we
2333 : : * explicitly do *not* want to block iterating over replication_slots or
2334 : : * acquiring a slot we cannot take the control lock - but that's OK,
2335 : : * because holding ReplicationSlotAllocationLock is strictly stronger, and
2336 : : * enough to guarantee that nobody can change the in_use bits on us.
2337 : : *
2338 : : * Additionally, acquiring the Allocation lock is necessary to serialize
2339 : : * the slot flush process with concurrent slot WAL reservation. This
2340 : : * ensures that the WAL position being reserved is either flushed to disk
2341 : : * or is beyond or equal to the redo pointer of the current checkpoint
2342 : : * (See ReplicationSlotReserveWal for details).
2343 : : */
4477 rhaas@postgresql.org 2344 : 1944 : LWLockAcquire(ReplicationSlotAllocationLock, LW_SHARED);
2345 : :
28 alvherre@kurilemu.de 2346 [ + + ]:GNC 30829 : for (i = 0; i < max_replication_slots + max_repack_replication_slots; i++)
2347 : : {
4477 rhaas@postgresql.org 2348 :CBC 28885 : ReplicationSlot *s = &ReplicationSlotCtl->replication_slots[i];
2349 : : char path[MAXPGPATH];
2350 : :
2351 [ + + ]: 28885 : if (!s->in_use)
2352 : 28473 : continue;
2353 : :
2354 : : /* save the slot to disk, locking is handled in SaveSlotToPath() */
613 michael@paquier.xyz 2355 : 412 : sprintf(path, "%s/%s", PG_REPLSLOT_DIR, NameStr(s->data.name));
2356 : :
2357 : : /*
2358 : : * Slot's data is not flushed each time the confirmed_flush LSN is
2359 : : * updated as that could lead to frequent writes. However, we decide
2360 : : * to force a flush of all logical slot's data at the time of shutdown
2361 : : * if the confirmed_flush LSN is changed since we last flushed it to
2362 : : * disk. This helps in avoiding an unnecessary retreat of the
2363 : : * confirmed_flush LSN after restart.
2364 : : */
964 akapila@postgresql.o 2365 [ + + + + ]: 412 : if (is_shutdown && SlotIsLogical(s))
2366 : : {
2367 [ - + ]: 92 : SpinLockAcquire(&s->mutex);
2368 : :
2369 [ + + ]: 92 : if (s->data.invalidated == RS_INVAL_NONE &&
693 2370 [ + + ]: 91 : s->data.confirmed_flush > s->last_saved_confirmed_flush)
2371 : : {
964 2372 : 41 : s->just_dirtied = true;
2373 : 41 : s->dirty = true;
2374 : : }
2375 : 92 : SpinLockRelease(&s->mutex);
2376 : : }
2377 : :
2378 : : /*
2379 : : * Track if we're going to update slot's last_saved_restart_lsn. We
2380 : : * need this to know if we need to recompute the required LSN.
2381 : : */
312 akorotkov@postgresql 2382 [ + + ]: 412 : if (s->last_saved_restart_lsn != s->data.restart_lsn)
2383 : 216 : last_saved_restart_lsn_updated = true;
2384 : :
4477 rhaas@postgresql.org 2385 : 412 : SaveSlotToPath(s, path, LOG);
2386 : : }
2387 : 1944 : LWLockRelease(ReplicationSlotAllocationLock);
2388 : :
2389 : : /*
2390 : : * Recompute the required LSN if SaveSlotToPath() updated
2391 : : * last_saved_restart_lsn for any slot.
2392 : : */
312 akorotkov@postgresql 2393 [ + + ]: 1944 : if (last_saved_restart_lsn_updated)
2394 : 216 : ReplicationSlotsComputeRequiredLSN();
4477 rhaas@postgresql.org 2395 : 1944 : }
2396 : :
2397 : : /*
2398 : : * Load all replication slots from disk into memory at server startup. This
2399 : : * needs to be run before we start crash recovery.
2400 : : */
2401 : : void
4345 andres@anarazel.de 2402 : 1079 : StartupReplicationSlots(void)
2403 : : {
2404 : : DIR *replication_dir;
2405 : : struct dirent *replication_de;
2406 : :
4193 peter_e@gmx.net 2407 [ + + ]: 1079 : elog(DEBUG1, "starting up replication slots");
2408 : :
2409 : : /* restore all slots by iterating over all on-disk entries */
613 michael@paquier.xyz 2410 : 1079 : replication_dir = AllocateDir(PG_REPLSLOT_DIR);
2411 [ + + ]: 3354 : while ((replication_de = ReadDir(replication_dir, PG_REPLSLOT_DIR)) != NULL)
2412 : : {
2413 : : char path[MAXPGPATH + sizeof(PG_REPLSLOT_DIR)];
2414 : : PGFileType de_type;
2415 : :
4477 rhaas@postgresql.org 2416 [ + + ]: 2277 : if (strcmp(replication_de->d_name, ".") == 0 ||
2417 [ + + ]: 1200 : strcmp(replication_de->d_name, "..") == 0)
2418 : 2154 : continue;
2419 : :
613 michael@paquier.xyz 2420 : 123 : snprintf(path, sizeof(path), "%s/%s", PG_REPLSLOT_DIR, replication_de->d_name);
1341 2421 : 123 : de_type = get_dirent_type(path, replication_de, false, DEBUG1);
2422 : :
2423 : : /* we're only creating directories here, skip if it's not our's */
2424 [ + - - + ]: 123 : if (de_type != PGFILETYPE_ERROR && de_type != PGFILETYPE_DIR)
4477 rhaas@postgresql.org 2425 :UBC 0 : continue;
2426 : :
2427 : : /* we crashed while a slot was being setup or deleted, clean up */
4140 andres@anarazel.de 2428 [ - + ]:CBC 123 : if (pg_str_endswith(replication_de->d_name, ".tmp"))
2429 : : {
4477 rhaas@postgresql.org 2430 [ # # ]:UBC 0 : if (!rmtree(path, true))
2431 : : {
2432 [ # # ]: 0 : ereport(WARNING,
2433 : : (errmsg("could not remove directory \"%s\"",
2434 : : path)));
2435 : 0 : continue;
2436 : : }
613 michael@paquier.xyz 2437 : 0 : fsync_fname(PG_REPLSLOT_DIR, true);
4477 rhaas@postgresql.org 2438 : 0 : continue;
2439 : : }
2440 : :
2441 : : /* looks like a slot in a normal state, restore */
4477 rhaas@postgresql.org 2442 :CBC 123 : RestoreSlotFromDisk(replication_de->d_name);
2443 : : }
2444 : 1077 : FreeDir(replication_dir);
2445 : :
2446 : : /* currently no slots exist, we're done. */
28 alvherre@kurilemu.de 2447 [ - + ]:GNC 1077 : if (max_replication_slots + max_repack_replication_slots <= 0)
4477 rhaas@postgresql.org 2448 :UBC 0 : return;
2449 : :
2450 : : /* Now that we have recovered all the data, compute replication xmin */
4446 rhaas@postgresql.org 2451 :CBC 1077 : ReplicationSlotsComputeRequiredXmin(false);
4477 2452 : 1077 : ReplicationSlotsComputeRequiredLSN();
2453 : : }
2454 : :
2455 : : /* ----
2456 : : * Manipulation of on-disk state of replication slots
2457 : : *
2458 : : * NB: none of the routines below should take any notice whether a slot is the
2459 : : * current one or not, that's all handled a layer above.
2460 : : * ----
2461 : : */
2462 : : static void
2463 : 712 : CreateSlotOnDisk(ReplicationSlot *slot)
2464 : : {
2465 : : char tmppath[MAXPGPATH];
2466 : : char path[MAXPGPATH];
2467 : : struct stat st;
2468 : :
2469 : : /*
2470 : : * No need to take out the io_in_progress_lock, nobody else can see this
2471 : : * slot yet, so nobody else will write. We're reusing SaveSlotToPath which
2472 : : * takes out the lock, if we'd take the lock here, we'd deadlock.
2473 : : */
2474 : :
613 michael@paquier.xyz 2475 : 712 : sprintf(path, "%s/%s", PG_REPLSLOT_DIR, NameStr(slot->data.name));
2476 : 712 : sprintf(tmppath, "%s/%s.tmp", PG_REPLSLOT_DIR, NameStr(slot->data.name));
2477 : :
2478 : : /*
2479 : : * It's just barely possible that some previous effort to create or drop a
2480 : : * slot with this name left a temp directory lying around. If that seems
2481 : : * to be the case, try to remove it. If the rmtree() fails, we'll error
2482 : : * out at the MakePGDirectory() below, so we don't bother checking
2483 : : * success.
2484 : : */
4477 rhaas@postgresql.org 2485 [ - + - - ]: 712 : if (stat(tmppath, &st) == 0 && S_ISDIR(st.st_mode))
4477 rhaas@postgresql.org 2486 :UBC 0 : rmtree(tmppath, true);
2487 : :
2488 : : /* Create and fsync the temporary slot directory. */
2950 sfrost@snowman.net 2489 [ - + ]:CBC 712 : if (MakePGDirectory(tmppath) < 0)
4477 rhaas@postgresql.org 2490 [ # # ]:UBC 0 : ereport(ERROR,
2491 : : (errcode_for_file_access(),
2492 : : errmsg("could not create directory \"%s\": %m",
2493 : : tmppath)));
4477 rhaas@postgresql.org 2494 :CBC 712 : fsync_fname(tmppath, true);
2495 : :
2496 : : /* Write the actual state file. */
4382 bruce@momjian.us 2497 : 712 : slot->dirty = true; /* signal that we really need to write */
4477 rhaas@postgresql.org 2498 : 712 : SaveSlotToPath(slot, tmppath, ERROR);
2499 : :
2500 : : /* Rename the directory into place. */
2501 [ - + ]: 712 : if (rename(tmppath, path) != 0)
4477 rhaas@postgresql.org 2502 [ # # ]:UBC 0 : ereport(ERROR,
2503 : : (errcode_for_file_access(),
2504 : : errmsg("could not rename file \"%s\" to \"%s\": %m",
2505 : : tmppath, path)));
2506 : :
2507 : : /*
2508 : : * If we'd now fail - really unlikely - we wouldn't know whether this slot
2509 : : * would persist after an OS crash or not - so, force a restart. The
2510 : : * restart would try to fsync this again till it works.
2511 : : */
4477 rhaas@postgresql.org 2512 :CBC 712 : START_CRIT_SECTION();
2513 : :
2514 : 712 : fsync_fname(path, true);
613 michael@paquier.xyz 2515 : 712 : fsync_fname(PG_REPLSLOT_DIR, true);
2516 : :
4477 rhaas@postgresql.org 2517 [ - + ]: 712 : END_CRIT_SECTION();
2518 : 712 : }
2519 : :
2520 : : /*
2521 : : * Shared functionality between saving and creating a replication slot.
2522 : : */
2523 : : static void
2524 : 2611 : SaveSlotToPath(ReplicationSlot *slot, const char *dir, int elevel)
2525 : : {
2526 : : char tmppath[MAXPGPATH];
2527 : : char path[MAXPGPATH];
2528 : : int fd;
2529 : : ReplicationSlotOnDisk cp;
2530 : : bool was_dirty;
2531 : :
2532 : : /* first check whether there's something to write out */
3864 2533 [ - + ]: 2611 : SpinLockAcquire(&slot->mutex);
2534 : 2611 : was_dirty = slot->dirty;
2535 : 2611 : slot->just_dirtied = false;
2536 : 2611 : SpinLockRelease(&slot->mutex);
2537 : :
2538 : : /* and don't do anything if there's nothing to write */
4477 2539 [ + + ]: 2611 : if (!was_dirty)
2540 : 144 : return;
2541 : :
3749 2542 : 2467 : LWLockAcquire(&slot->io_in_progress_lock, LW_EXCLUSIVE);
2543 : :
2544 : : /* silence valgrind :( */
4477 2545 : 2467 : memset(&cp, 0, sizeof(ReplicationSlotOnDisk));
2546 : :
2547 : 2467 : sprintf(tmppath, "%s/state.tmp", dir);
2548 : 2467 : sprintf(path, "%s/state", dir);
2549 : :
3146 peter_e@gmx.net 2550 : 2467 : fd = OpenTransientFile(tmppath, O_CREAT | O_EXCL | O_WRONLY | PG_BINARY);
4477 rhaas@postgresql.org 2551 [ - + ]: 2467 : if (fd < 0)
2552 : : {
2553 : : /*
2554 : : * If not an ERROR, then release the lock before returning. In case
2555 : : * of an ERROR, the error recovery path automatically releases the
2556 : : * lock, but no harm in explicitly releasing even in that case. Note
2557 : : * that LWLockRelease() could affect errno.
2558 : : */
2221 peter@eisentraut.org 2559 :UBC 0 : int save_errno = errno;
2560 : :
2231 2561 : 0 : LWLockRelease(&slot->io_in_progress_lock);
2221 2562 : 0 : errno = save_errno;
4477 rhaas@postgresql.org 2563 [ # # ]: 0 : ereport(elevel,
2564 : : (errcode_for_file_access(),
2565 : : errmsg("could not create file \"%s\": %m",
2566 : : tmppath)));
2567 : 0 : return;
2568 : : }
2569 : :
4477 rhaas@postgresql.org 2570 :CBC 2467 : cp.magic = SLOT_MAGIC;
4200 heikki.linnakangas@i 2571 : 2467 : INIT_CRC32C(cp.checksum);
4192 andres@anarazel.de 2572 : 2467 : cp.version = SLOT_VERSION;
2573 : 2467 : cp.length = ReplicationSlotOnDiskV2Size;
2574 : :
4477 rhaas@postgresql.org 2575 [ - + ]: 2467 : SpinLockAcquire(&slot->mutex);
2576 : :
2577 : 2467 : memcpy(&cp.slotdata, &slot->data, sizeof(ReplicationSlotPersistentData));
2578 : :
2579 : 2467 : SpinLockRelease(&slot->mutex);
2580 : :
4200 heikki.linnakangas@i 2581 : 2467 : COMP_CRC32C(cp.checksum,
2582 : : (char *) (&cp) + ReplicationSlotOnDiskNotChecksummedSize,
2583 : : ReplicationSlotOnDiskChecksummedSize);
4192 andres@anarazel.de 2584 : 2467 : FIN_CRC32C(cp.checksum);
2585 : :
2830 michael@paquier.xyz 2586 : 2467 : errno = 0;
3335 rhaas@postgresql.org 2587 : 2467 : pgstat_report_wait_start(WAIT_EVENT_REPLICATION_SLOT_WRITE);
4477 2588 [ - + ]: 2467 : if ((write(fd, &cp, sizeof(cp))) != sizeof(cp))
2589 : : {
4382 bruce@momjian.us 2590 :UBC 0 : int save_errno = errno;
2591 : :
3335 rhaas@postgresql.org 2592 : 0 : pgstat_report_wait_end();
4477 2593 : 0 : CloseTransientFile(fd);
207 michael@paquier.xyz 2594 : 0 : unlink(tmppath);
2231 peter@eisentraut.org 2595 : 0 : LWLockRelease(&slot->io_in_progress_lock);
2596 : :
2597 : : /* if write didn't set errno, assume problem is no disk space */
2871 michael@paquier.xyz 2598 [ # # ]: 0 : errno = save_errno ? save_errno : ENOSPC;
4477 rhaas@postgresql.org 2599 [ # # ]: 0 : ereport(elevel,
2600 : : (errcode_for_file_access(),
2601 : : errmsg("could not write to file \"%s\": %m",
2602 : : tmppath)));
2603 : 0 : return;
2604 : : }
3335 rhaas@postgresql.org 2605 :CBC 2467 : pgstat_report_wait_end();
2606 : :
2607 : : /* fsync the temporary file */
2608 : 2467 : pgstat_report_wait_start(WAIT_EVENT_REPLICATION_SLOT_SYNC);
4477 2609 [ - + ]: 2467 : if (pg_fsync(fd) != 0)
2610 : : {
4382 bruce@momjian.us 2611 :UBC 0 : int save_errno = errno;
2612 : :
3335 rhaas@postgresql.org 2613 : 0 : pgstat_report_wait_end();
4477 2614 : 0 : CloseTransientFile(fd);
207 michael@paquier.xyz 2615 : 0 : unlink(tmppath);
2231 peter@eisentraut.org 2616 : 0 : LWLockRelease(&slot->io_in_progress_lock);
2617 : :
4477 rhaas@postgresql.org 2618 : 0 : errno = save_errno;
2619 [ # # ]: 0 : ereport(elevel,
2620 : : (errcode_for_file_access(),
2621 : : errmsg("could not fsync file \"%s\": %m",
2622 : : tmppath)));
2623 : 0 : return;
2624 : : }
3335 rhaas@postgresql.org 2625 :CBC 2467 : pgstat_report_wait_end();
2626 : :
2495 peter@eisentraut.org 2627 [ - + ]: 2467 : if (CloseTransientFile(fd) != 0)
2628 : : {
2221 peter@eisentraut.org 2629 :UBC 0 : int save_errno = errno;
2630 : :
207 michael@paquier.xyz 2631 : 0 : unlink(tmppath);
2231 peter@eisentraut.org 2632 : 0 : LWLockRelease(&slot->io_in_progress_lock);
2633 : :
2221 2634 : 0 : errno = save_errno;
2614 michael@paquier.xyz 2635 [ # # ]: 0 : ereport(elevel,
2636 : : (errcode_for_file_access(),
2637 : : errmsg("could not close file \"%s\": %m",
2638 : : tmppath)));
2575 2639 : 0 : return;
2640 : : }
2641 : :
2642 : : /* rename to permanent file, fsync file and directory */
4477 rhaas@postgresql.org 2643 [ - + ]:CBC 2467 : if (rename(tmppath, path) != 0)
2644 : : {
2221 peter@eisentraut.org 2645 :UBC 0 : int save_errno = errno;
2646 : :
207 michael@paquier.xyz 2647 : 0 : unlink(tmppath);
2231 peter@eisentraut.org 2648 : 0 : LWLockRelease(&slot->io_in_progress_lock);
2649 : :
2221 2650 : 0 : errno = save_errno;
4477 rhaas@postgresql.org 2651 [ # # ]: 0 : ereport(elevel,
2652 : : (errcode_for_file_access(),
2653 : : errmsg("could not rename file \"%s\" to \"%s\": %m",
2654 : : tmppath, path)));
2655 : 0 : return;
2656 : : }
2657 : :
2658 : : /*
2659 : : * Check CreateSlotOnDisk() for the reasoning of using a critical section.
2660 : : */
4477 rhaas@postgresql.org 2661 :CBC 2467 : START_CRIT_SECTION();
2662 : :
2663 : 2467 : fsync_fname(path, false);
3709 andres@anarazel.de 2664 : 2467 : fsync_fname(dir, true);
613 michael@paquier.xyz 2665 : 2467 : fsync_fname(PG_REPLSLOT_DIR, true);
2666 : :
4477 rhaas@postgresql.org 2667 [ - + ]: 2467 : END_CRIT_SECTION();
2668 : :
2669 : : /*
2670 : : * Successfully wrote, unset dirty bit, unless somebody dirtied again
2671 : : * already and remember the confirmed_flush LSN value.
2672 : : */
3864 2673 [ - + ]: 2467 : SpinLockAcquire(&slot->mutex);
2674 [ + + ]: 2467 : if (!slot->just_dirtied)
2675 : 2459 : slot->dirty = false;
964 akapila@postgresql.o 2676 : 2467 : slot->last_saved_confirmed_flush = cp.slotdata.confirmed_flush;
325 akorotkov@postgresql 2677 : 2467 : slot->last_saved_restart_lsn = cp.slotdata.restart_lsn;
3864 rhaas@postgresql.org 2678 : 2467 : SpinLockRelease(&slot->mutex);
2679 : :
3749 2680 : 2467 : LWLockRelease(&slot->io_in_progress_lock);
2681 : : }
2682 : :
2683 : : /*
2684 : : * Load a single slot from disk into memory.
2685 : : */
2686 : : static void
4477 2687 : 123 : RestoreSlotFromDisk(const char *name)
2688 : : {
2689 : : ReplicationSlotOnDisk cp;
2690 : : int i;
2691 : : char slotdir[MAXPGPATH + sizeof(PG_REPLSLOT_DIR)];
2692 : : char path[MAXPGPATH + sizeof(PG_REPLSLOT_DIR) + 10];
2693 : : int fd;
2694 : 123 : bool restored = false;
2695 : : int readBytes;
2696 : : pg_crc32c checksum;
454 akapila@postgresql.o 2697 : 123 : TimestampTz now = 0;
2698 : :
2699 : : /* no need to lock here, no concurrent access allowed yet */
2700 : :
2701 : : /* delete temp file if it exists */
613 michael@paquier.xyz 2702 : 123 : sprintf(slotdir, "%s/%s", PG_REPLSLOT_DIR, name);
2802 2703 : 123 : sprintf(path, "%s/state.tmp", slotdir);
4477 rhaas@postgresql.org 2704 [ + - - + ]: 123 : if (unlink(path) < 0 && errno != ENOENT)
4477 rhaas@postgresql.org 2705 [ # # ]:UBC 0 : ereport(PANIC,
2706 : : (errcode_for_file_access(),
2707 : : errmsg("could not remove file \"%s\": %m", path)));
2708 : :
2802 michael@paquier.xyz 2709 :CBC 123 : sprintf(path, "%s/state", slotdir);
2710 : :
4477 rhaas@postgresql.org 2711 [ + + ]: 123 : elog(DEBUG1, "restoring replication slot from \"%s\"", path);
2712 : :
2713 : : /* on some operating systems fsyncing a file requires O_RDWR */
2405 andres@anarazel.de 2714 : 123 : fd = OpenTransientFile(path, O_RDWR | PG_BINARY);
2715 : :
2716 : : /*
2717 : : * We do not need to handle this as we are rename()ing the directory into
2718 : : * place only after we fsync()ed the state file.
2719 : : */
4477 rhaas@postgresql.org 2720 [ - + ]: 123 : if (fd < 0)
4477 rhaas@postgresql.org 2721 [ # # ]:UBC 0 : ereport(PANIC,
2722 : : (errcode_for_file_access(),
2723 : : errmsg("could not open file \"%s\": %m", path)));
2724 : :
2725 : : /*
2726 : : * Sync state file before we're reading from it. We might have crashed
2727 : : * while it wasn't synced yet and we shouldn't continue on that basis.
2728 : : */
3335 rhaas@postgresql.org 2729 :CBC 123 : pgstat_report_wait_start(WAIT_EVENT_REPLICATION_SLOT_RESTORE_SYNC);
4477 2730 [ - + ]: 123 : if (pg_fsync(fd) != 0)
4477 rhaas@postgresql.org 2731 [ # # ]:UBC 0 : ereport(PANIC,
2732 : : (errcode_for_file_access(),
2733 : : errmsg("could not fsync file \"%s\": %m",
2734 : : path)));
3335 rhaas@postgresql.org 2735 :CBC 123 : pgstat_report_wait_end();
2736 : :
2737 : : /* Also sync the parent directory */
4477 2738 : 123 : START_CRIT_SECTION();
2802 michael@paquier.xyz 2739 : 123 : fsync_fname(slotdir, true);
4477 rhaas@postgresql.org 2740 [ - + ]: 123 : END_CRIT_SECTION();
2741 : :
2742 : : /* read part of statefile that's guaranteed to be version independent */
3335 2743 : 123 : pgstat_report_wait_start(WAIT_EVENT_REPLICATION_SLOT_READ);
4477 2744 : 123 : readBytes = read(fd, &cp, ReplicationSlotOnDiskConstantSize);
3335 2745 : 123 : pgstat_report_wait_end();
4477 2746 [ - + ]: 123 : if (readBytes != ReplicationSlotOnDiskConstantSize)
2747 : : {
2848 michael@paquier.xyz 2748 [ # # ]:UBC 0 : if (readBytes < 0)
2749 [ # # ]: 0 : ereport(PANIC,
2750 : : (errcode_for_file_access(),
2751 : : errmsg("could not read file \"%s\": %m", path)));
2752 : : else
2753 [ # # ]: 0 : ereport(PANIC,
2754 : : (errcode(ERRCODE_DATA_CORRUPTED),
2755 : : errmsg("could not read file \"%s\": read %d of %zu",
2756 : : path, readBytes,
2757 : : (Size) ReplicationSlotOnDiskConstantSize)));
2758 : : }
2759 : :
2760 : : /* verify magic */
4477 rhaas@postgresql.org 2761 [ - + ]:CBC 123 : if (cp.magic != SLOT_MAGIC)
4477 rhaas@postgresql.org 2762 [ # # ]:UBC 0 : ereport(PANIC,
2763 : : (errcode(ERRCODE_DATA_CORRUPTED),
2764 : : errmsg("replication slot file \"%s\" has wrong magic number: %u instead of %u",
2765 : : path, cp.magic, SLOT_MAGIC)));
2766 : :
2767 : : /* verify version */
4477 rhaas@postgresql.org 2768 [ - + ]:CBC 123 : if (cp.version != SLOT_VERSION)
4477 rhaas@postgresql.org 2769 [ # # ]:UBC 0 : ereport(PANIC,
2770 : : (errcode(ERRCODE_DATA_CORRUPTED),
2771 : : errmsg("replication slot file \"%s\" has unsupported version %u",
2772 : : path, cp.version)));
2773 : :
2774 : : /* boundary check on length */
4192 andres@anarazel.de 2775 [ - + ]:CBC 123 : if (cp.length != ReplicationSlotOnDiskV2Size)
4477 rhaas@postgresql.org 2776 [ # # ]:UBC 0 : ereport(PANIC,
2777 : : (errcode(ERRCODE_DATA_CORRUPTED),
2778 : : errmsg("replication slot file \"%s\" has corrupted length %u",
2779 : : path, cp.length)));
2780 : :
2781 : : /* Now that we know the size, read the entire file */
3335 rhaas@postgresql.org 2782 :CBC 123 : pgstat_report_wait_start(WAIT_EVENT_REPLICATION_SLOT_READ);
4477 2783 : 246 : readBytes = read(fd,
2784 : : (char *) &cp + ReplicationSlotOnDiskConstantSize,
2785 : 123 : cp.length);
3335 2786 : 123 : pgstat_report_wait_end();
4477 2787 [ - + ]: 123 : if (readBytes != cp.length)
2788 : : {
2848 michael@paquier.xyz 2789 [ # # ]:UBC 0 : if (readBytes < 0)
2790 [ # # ]: 0 : ereport(PANIC,
2791 : : (errcode_for_file_access(),
2792 : : errmsg("could not read file \"%s\": %m", path)));
2793 : : else
2794 [ # # ]: 0 : ereport(PANIC,
2795 : : (errcode(ERRCODE_DATA_CORRUPTED),
2796 : : errmsg("could not read file \"%s\": read %d of %zu",
2797 : : path, readBytes, (Size) cp.length)));
2798 : : }
2799 : :
2495 peter@eisentraut.org 2800 [ - + ]:CBC 123 : if (CloseTransientFile(fd) != 0)
2614 michael@paquier.xyz 2801 [ # # ]:UBC 0 : ereport(PANIC,
2802 : : (errcode_for_file_access(),
2803 : : errmsg("could not close file \"%s\": %m", path)));
2804 : :
2805 : : /* now verify the CRC */
4200 heikki.linnakangas@i 2806 :CBC 123 : INIT_CRC32C(checksum);
2807 : 123 : COMP_CRC32C(checksum,
2808 : : (char *) &cp + ReplicationSlotOnDiskNotChecksummedSize,
2809 : : ReplicationSlotOnDiskChecksummedSize);
4192 andres@anarazel.de 2810 : 123 : FIN_CRC32C(checksum);
2811 : :
4200 heikki.linnakangas@i 2812 [ - + ]: 123 : if (!EQ_CRC32C(checksum, cp.checksum))
4477 rhaas@postgresql.org 2813 [ # # ]:UBC 0 : ereport(PANIC,
2814 : : (errmsg("checksum mismatch for replication slot file \"%s\": is %u, should be %u",
2815 : : path, checksum, cp.checksum)));
2816 : :
2817 : : /*
2818 : : * If we crashed with an ephemeral slot active, don't restore but delete
2819 : : * it.
2820 : : */
4303 andres@anarazel.de 2821 [ - + ]:CBC 123 : if (cp.slotdata.persistency != RS_PERSISTENT)
2822 : : {
2802 michael@paquier.xyz 2823 [ # # ]:UBC 0 : if (!rmtree(slotdir, true))
2824 : : {
4303 andres@anarazel.de 2825 [ # # ]: 0 : ereport(WARNING,
2826 : : (errmsg("could not remove directory \"%s\"",
2827 : : slotdir)));
2828 : : }
613 michael@paquier.xyz 2829 : 0 : fsync_fname(PG_REPLSLOT_DIR, true);
4303 andres@anarazel.de 2830 : 0 : return;
2831 : : }
2832 : :
2833 : : /*
2834 : : * Verify that requirements for the specific slot type are met. That's
2835 : : * important because if these aren't met we're not guaranteed to retain
2836 : : * all the necessary resources for the slot.
2837 : : *
2838 : : * NB: We have to do so *after* the above checks for ephemeral slots,
2839 : : * because otherwise a slot that shouldn't exist anymore could prevent
2840 : : * restarts.
2841 : : *
2842 : : * NB: Changing the requirements here also requires adapting
2843 : : * CheckSlotRequirements() and CheckLogicalDecodingRequirements().
2844 : : */
435 msawada@postgresql.o 2845 [ + + ]:CBC 123 : if (cp.slotdata.database != InvalidOid)
2846 : : {
133 msawada@postgresql.o 2847 [ + + ]:GNC 85 : if (wal_level < WAL_LEVEL_REPLICA)
435 msawada@postgresql.o 2848 [ + - ]:GBC 1 : ereport(FATAL,
2849 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
2850 : : errmsg("logical replication slot \"%s\" exists, but \"wal_level\" < \"replica\"",
2851 : : NameStr(cp.slotdata.name)),
2852 : : errhint("Change \"wal_level\" to be \"replica\" or higher.")));
2853 : :
2854 : : /*
2855 : : * In standby mode, the hot standby must be enabled. This check is
2856 : : * necessary to ensure logical slots are invalidated when they become
2857 : : * incompatible due to insufficient wal_level. Otherwise, if the
2858 : : * primary reduces effective_wal_level < logical while hot standby is
2859 : : * disabled, primary disable logical decoding while hot standby is
2860 : : * disabled, logical slots would remain valid even after promotion.
2861 : : */
435 msawada@postgresql.o 2862 [ + + + + ]:CBC 84 : if (StandbyMode && !EnableHotStandby)
2863 [ + - ]: 1 : ereport(FATAL,
2864 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
2865 : : errmsg("logical replication slot \"%s\" exists on the standby, but \"hot_standby\" = \"off\"",
2866 : : NameStr(cp.slotdata.name)),
2867 : : errhint("Change \"hot_standby\" to be \"on\".")));
2868 : : }
2743 andres@anarazel.de 2869 [ - + ]: 38 : else if (wal_level < WAL_LEVEL_REPLICA)
2743 andres@anarazel.de 2870 [ # # ]:UBC 0 : ereport(FATAL,
2871 : : (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
2872 : : errmsg("physical replication slot \"%s\" exists, but \"wal_level\" < \"replica\"",
2873 : : NameStr(cp.slotdata.name)),
2874 : : errhint("Change \"wal_level\" to be \"replica\" or higher.")));
2875 : :
2876 : : /*
2877 : : * Nothing can be active yet, don't lock anything. Note we iterate up to
2878 : : * max_replication_slots instead of adding max_repack_replication_slots as
2879 : : * in all other places, because we must enforce the GUC value in case
2880 : : * there were more slots before the shutdown than what it is set up to
2881 : : * now.
2882 : : */
4477 rhaas@postgresql.org 2883 [ + - ]:CBC 178 : for (i = 0; i < max_replication_slots; i++)
2884 : : {
2885 : : ReplicationSlot *slot;
2886 : :
2887 : 178 : slot = &ReplicationSlotCtl->replication_slots[i];
2888 : :
2889 [ + + ]: 178 : if (slot->in_use)
2890 : 57 : continue;
2891 : :
2892 : : /* restore the entire set of persistent data */
2893 : 121 : memcpy(&slot->data, &cp.slotdata,
2894 : : sizeof(ReplicationSlotPersistentData));
2895 : :
2896 : : /* initialize in memory state */
2897 : 121 : slot->effective_xmin = cp.slotdata.xmin;
4446 2898 : 121 : slot->effective_catalog_xmin = cp.slotdata.catalog_xmin;
964 akapila@postgresql.o 2899 : 121 : slot->last_saved_confirmed_flush = cp.slotdata.confirmed_flush;
325 akorotkov@postgresql 2900 : 121 : slot->last_saved_restart_lsn = cp.slotdata.restart_lsn;
2901 : :
4446 rhaas@postgresql.org 2902 : 121 : slot->candidate_catalog_xmin = InvalidTransactionId;
2903 : 121 : slot->candidate_xmin_lsn = InvalidXLogRecPtr;
2904 : 121 : slot->candidate_restart_lsn = InvalidXLogRecPtr;
2905 : 121 : slot->candidate_restart_valid = InvalidXLogRecPtr;
2906 : :
4477 2907 : 121 : slot->in_use = true;
84 heikki.linnakangas@i 2908 :GNC 121 : slot->active_proc = INVALID_PROC_NUMBER;
2909 : :
2910 : : /*
2911 : : * Set the time since the slot has become inactive after loading the
2912 : : * slot from the disk into memory. Whoever acquires the slot i.e.
2913 : : * makes the slot active will reset it. Use the same inactive_since
2914 : : * time for all the slots.
2915 : : */
454 akapila@postgresql.o 2916 [ + - ]:CBC 121 : if (now == 0)
2917 : 121 : now = GetCurrentTimestamp();
2918 : :
2919 : 121 : ReplicationSlotSetInactiveSince(slot, now, false);
2920 : :
4477 rhaas@postgresql.org 2921 : 121 : restored = true;
2922 : 121 : break;
2923 : : }
2924 : :
2925 [ - + ]: 121 : if (!restored)
2741 michael@paquier.xyz 2926 [ # # ]:UBC 0 : ereport(FATAL,
2927 : : (errmsg("too many replication slots active before shutdown"),
2928 : : errhint("Increase \"max_replication_slots\" and try again.")));
2929 : : }
2930 : :
2931 : : /*
2932 : : * Maps an invalidation reason for a replication slot to
2933 : : * ReplicationSlotInvalidationCause.
2934 : : */
2935 : : ReplicationSlotInvalidationCause
440 akapila@postgresql.o 2936 : 0 : GetSlotInvalidationCause(const char *cause_name)
2937 : : {
2938 [ # # ]: 0 : Assert(cause_name);
2939 : :
2940 : : /* Search lookup table for the cause having this name */
2941 [ # # ]: 0 : for (int i = 0; i <= RS_INVAL_MAX_CAUSES; i++)
2942 : : {
2943 [ # # ]: 0 : if (strcmp(SlotInvalidationCauses[i].cause_name, cause_name) == 0)
2944 : 0 : return SlotInvalidationCauses[i].cause;
2945 : : }
2946 : :
2947 : 0 : Assert(false);
2948 : : return RS_INVAL_NONE; /* to keep compiler quiet */
2949 : : }
2950 : :
2951 : : /*
2952 : : * Maps a ReplicationSlotInvalidationCause to the invalidation
2953 : : * reason for a replication slot.
2954 : : */
2955 : : const char *
440 akapila@postgresql.o 2956 :CBC 44 : GetSlotInvalidationCauseName(ReplicationSlotInvalidationCause cause)
2957 : : {
2958 : : /* Search lookup table for the name of this cause */
2959 [ + - ]: 141 : for (int i = 0; i <= RS_INVAL_MAX_CAUSES; i++)
2960 : : {
2961 [ + + ]: 141 : if (SlotInvalidationCauses[i].cause == cause)
2962 : 44 : return SlotInvalidationCauses[i].cause_name;
2963 : : }
2964 : :
440 akapila@postgresql.o 2965 :UBC 0 : Assert(false);
2966 : : return "none"; /* to keep compiler quiet */
2967 : : }
2968 : :
2969 : : /*
2970 : : * A helper function to validate slots specified in GUC synchronized_standby_slots.
2971 : : *
2972 : : * The rawname will be parsed, and the result will be saved into *elemlist.
2973 : : */
2974 : : static bool
673 akapila@postgresql.o 2975 :CBC 28 : validate_sync_standby_slots(char *rawname, List **elemlist)
2976 : : {
2977 : : /* Verify syntax and parse string into a list of identifiers */
190 2978 [ - + ]: 28 : if (!SplitIdentifierString(rawname, ',', elemlist))
2979 : : {
788 akapila@postgresql.o 2980 :UBC 0 : GUC_check_errdetail("List syntax is invalid.");
190 2981 : 0 : return false;
2982 : : }
2983 : :
2984 : : /* Iterate the list to validate each slot name */
190 akapila@postgresql.o 2985 [ + - + + :CBC 80 : foreach_ptr(char, name, *elemlist)
+ + ]
2986 : : {
2987 : : int err_code;
2988 : 28 : char *err_msg = NULL;
2989 : 28 : char *err_hint = NULL;
2990 : :
190 akapila@postgresql.o 2991 [ + + ]:GNC 28 : if (!ReplicationSlotValidateNameInternal(name, false, &err_code,
2992 : : &err_msg, &err_hint))
2993 : : {
190 akapila@postgresql.o 2994 :CBC 2 : GUC_check_errcode(err_code);
2995 : 2 : GUC_check_errdetail("%s", err_msg);
2996 [ + - ]: 2 : if (err_hint != NULL)
2997 : 2 : GUC_check_errhint("%s", err_hint);
2998 : 2 : return false;
2999 : : }
3000 : : }
3001 : :
3002 : 26 : return true;
3003 : : }
3004 : :
3005 : : /*
3006 : : * GUC check_hook for synchronized_standby_slots
3007 : : */
3008 : : bool
673 3009 : 1327 : check_synchronized_standby_slots(char **newval, void **extra, GucSource source)
3010 : : {
3011 : : char *rawname;
3012 : : char *ptr;
3013 : : List *elemlist;
3014 : : int size;
3015 : : bool ok;
3016 : : SyncStandbySlotsConfigData *config;
3017 : :
788 3018 [ + + ]: 1327 : if ((*newval)[0] == '\0')
3019 : 1299 : return true;
3020 : :
3021 : : /* Need a modifiable copy of the GUC string */
3022 : 28 : rawname = pstrdup(*newval);
3023 : :
3024 : : /* Now verify if the specified slots exist and have correct type */
673 3025 : 28 : ok = validate_sync_standby_slots(rawname, &elemlist);
3026 : :
788 3027 [ + + - + ]: 28 : if (!ok || elemlist == NIL)
3028 : : {
3029 : 2 : pfree(rawname);
3030 : 2 : list_free(elemlist);
3031 : 2 : return ok;
3032 : : }
3033 : :
3034 : : /* Compute the size required for the SyncStandbySlotsConfigData struct */
673 3035 : 26 : size = offsetof(SyncStandbySlotsConfigData, slot_names);
788 3036 [ + - + + : 78 : foreach_ptr(char, slot_name, elemlist)
+ + ]
3037 : 26 : size += strlen(slot_name) + 1;
3038 : :
3039 : : /* GUC extra value must be guc_malloc'd, not palloc'd */
673 3040 : 26 : config = (SyncStandbySlotsConfigData *) guc_malloc(LOG, size);
404 dgustafsson@postgres 3041 [ - + ]: 26 : if (!config)
404 dgustafsson@postgres 3042 :UBC 0 : return false;
3043 : :
3044 : : /* Transform the data into SyncStandbySlotsConfigData */
788 akapila@postgresql.o 3045 :CBC 26 : config->nslotnames = list_length(elemlist);
3046 : :
3047 : 26 : ptr = config->slot_names;
3048 [ + - + + : 78 : foreach_ptr(char, slot_name, elemlist)
+ + ]
3049 : : {
3050 : 26 : strcpy(ptr, slot_name);
3051 : 26 : ptr += strlen(slot_name) + 1;
3052 : : }
3053 : :
523 peter@eisentraut.org 3054 : 26 : *extra = config;
3055 : :
788 akapila@postgresql.o 3056 : 26 : pfree(rawname);
3057 : 26 : list_free(elemlist);
3058 : 26 : return true;
3059 : : }
3060 : :
3061 : : /*
3062 : : * GUC assign_hook for synchronized_standby_slots
3063 : : */
3064 : : void
673 3065 : 1324 : assign_synchronized_standby_slots(const char *newval, void *extra)
3066 : : {
3067 : : /*
3068 : : * The standby slots may have changed, so we must recompute the oldest
3069 : : * LSN.
3070 : : */
788 3071 : 1324 : ss_oldest_flush_lsn = InvalidXLogRecPtr;
3072 : :
673 3073 : 1324 : synchronized_standby_slots_config = (SyncStandbySlotsConfigData *) extra;
788 3074 : 1324 : }
3075 : :
3076 : : /*
3077 : : * Check if the passed slot_name is specified in the synchronized_standby_slots GUC.
3078 : : */
3079 : : bool
673 3080 : 41898 : SlotExistsInSyncStandbySlots(const char *slot_name)
3081 : : {
3082 : : const char *standby_slot_name;
3083 : :
3084 : : /* Return false if there is no value in synchronized_standby_slots */
3085 [ + + ]: 41898 : if (synchronized_standby_slots_config == NULL)
788 3086 : 41882 : return false;
3087 : :
3088 : : /*
3089 : : * XXX: We are not expecting this list to be long so a linear search
3090 : : * shouldn't hurt but if that turns out not to be true then we can cache
3091 : : * this information for each WalSender as well.
3092 : : */
673 3093 : 16 : standby_slot_name = synchronized_standby_slots_config->slot_names;
3094 [ + + ]: 24 : for (int i = 0; i < synchronized_standby_slots_config->nslotnames; i++)
3095 : : {
788 3096 [ + + ]: 16 : if (strcmp(standby_slot_name, slot_name) == 0)
3097 : 8 : return true;
3098 : :
788 akapila@postgresql.o 3099 :GBC 8 : standby_slot_name += strlen(standby_slot_name) + 1;
3100 : : }
3101 : :
3102 : 8 : return false;
3103 : : }
3104 : :
3105 : : /*
3106 : : * Return true if the slots specified in synchronized_standby_slots have caught up to
3107 : : * the given WAL location, false otherwise.
3108 : : *
3109 : : * The elevel parameter specifies the error level used for logging messages
3110 : : * related to slots that do not exist, are invalidated, or are inactive.
3111 : : */
3112 : : bool
788 akapila@postgresql.o 3113 :CBC 2440 : StandbySlotsHaveCaughtup(XLogRecPtr wait_for_lsn, int elevel)
3114 : : {
3115 : : const char *name;
3116 : 2440 : int caught_up_slot_num = 0;
3117 : 2440 : XLogRecPtr min_restart_lsn = InvalidXLogRecPtr;
3118 : :
3119 : : /*
3120 : : * Don't need to wait for the standbys to catch up if there is no value in
3121 : : * synchronized_standby_slots.
3122 : : */
673 3123 [ + + ]: 2440 : if (synchronized_standby_slots_config == NULL)
788 3124 : 2411 : return true;
3125 : :
3126 : : /*
3127 : : * Don't need to wait for the standbys to catch up if we are on a standby
3128 : : * server, since we do not support syncing slots to cascading standbys.
3129 : : */
3130 [ - + ]: 29 : if (RecoveryInProgress())
788 akapila@postgresql.o 3131 :UBC 0 : return true;
3132 : :
3133 : : /*
3134 : : * Don't need to wait for the standbys to catch up if they are already
3135 : : * beyond the specified WAL location.
3136 : : */
180 alvherre@kurilemu.de 3137 [ + + ]:GNC 29 : if (XLogRecPtrIsValid(ss_oldest_flush_lsn) &&
788 akapila@postgresql.o 3138 [ + + ]:CBC 18 : ss_oldest_flush_lsn >= wait_for_lsn)
3139 : 9 : return true;
3140 : :
3141 : : /*
3142 : : * To prevent concurrent slot dropping and creation while filtering the
3143 : : * slots, take the ReplicationSlotControlLock outside of the loop.
3144 : : */
3145 : 20 : LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
3146 : :
673 3147 : 20 : name = synchronized_standby_slots_config->slot_names;
3148 [ + + ]: 27 : for (int i = 0; i < synchronized_standby_slots_config->nslotnames; i++)
3149 : : {
3150 : : XLogRecPtr restart_lsn;
3151 : : bool invalidated;
3152 : : bool inactive;
3153 : : ReplicationSlot *slot;
3154 : :
788 3155 : 20 : slot = SearchNamedReplicationSlot(name, false);
3156 : :
3157 : : /*
3158 : : * If a slot name provided in synchronized_standby_slots does not
3159 : : * exist, report a message and exit the loop.
3160 : : */
3161 [ - + ]: 20 : if (!slot)
3162 : : {
788 akapila@postgresql.o 3163 [ # # ]:UBC 0 : ereport(elevel,
3164 : : errcode(ERRCODE_INVALID_PARAMETER_VALUE),
3165 : : errmsg("replication slot \"%s\" specified in parameter \"%s\" does not exist",
3166 : : name, "synchronized_standby_slots"),
3167 : : errdetail("Logical replication is waiting on the standby associated with replication slot \"%s\".",
3168 : : name),
3169 : : errhint("Create the replication slot \"%s\" or amend parameter \"%s\".",
3170 : : name, "synchronized_standby_slots"));
3171 : 0 : break;
3172 : : }
3173 : :
3174 : : /* Same as above: if a slot is not physical, exit the loop. */
788 akapila@postgresql.o 3175 [ - + ]:CBC 20 : if (SlotIsLogical(slot))
3176 : : {
788 akapila@postgresql.o 3177 [ # # ]:UBC 0 : ereport(elevel,
3178 : : errcode(ERRCODE_INVALID_PARAMETER_VALUE),
3179 : : errmsg("cannot specify logical replication slot \"%s\" in parameter \"%s\"",
3180 : : name, "synchronized_standby_slots"),
3181 : : errdetail("Logical replication is waiting for correction on replication slot \"%s\".",
3182 : : name),
3183 : : errhint("Remove the logical replication slot \"%s\" from parameter \"%s\".",
3184 : : name, "synchronized_standby_slots"));
3185 : 0 : break;
3186 : : }
3187 : :
788 akapila@postgresql.o 3188 [ - + ]:CBC 20 : SpinLockAcquire(&slot->mutex);
3189 : 20 : restart_lsn = slot->data.restart_lsn;
3190 : 20 : invalidated = slot->data.invalidated != RS_INVAL_NONE;
84 heikki.linnakangas@i 3191 :GNC 20 : inactive = slot->active_proc == INVALID_PROC_NUMBER;
788 akapila@postgresql.o 3192 :CBC 20 : SpinLockRelease(&slot->mutex);
3193 : :
3194 [ - + ]: 20 : if (invalidated)
3195 : : {
3196 : : /* Specified physical slot has been invalidated */
788 akapila@postgresql.o 3197 [ # # ]:UBC 0 : ereport(elevel,
3198 : : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3199 : : errmsg("physical replication slot \"%s\" specified in parameter \"%s\" has been invalidated",
3200 : : name, "synchronized_standby_slots"),
3201 : : errdetail("Logical replication is waiting on the standby associated with replication slot \"%s\".",
3202 : : name),
3203 : : errhint("Drop and recreate the replication slot \"%s\", or amend parameter \"%s\".",
3204 : : name, "synchronized_standby_slots"));
3205 : 0 : break;
3206 : : }
3207 : :
180 alvherre@kurilemu.de 3208 [ + + + + ]:GNC 20 : if (!XLogRecPtrIsValid(restart_lsn) || restart_lsn < wait_for_lsn)
3209 : : {
3210 : : /* Log a message if no active_pid for this physical slot */
788 akapila@postgresql.o 3211 [ + + ]:CBC 13 : if (inactive)
3212 [ + - ]: 7 : ereport(elevel,
3213 : : errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
3214 : : errmsg("replication slot \"%s\" specified in parameter \"%s\" does not have active_pid",
3215 : : name, "synchronized_standby_slots"),
3216 : : errdetail("Logical replication is waiting on the standby associated with replication slot \"%s\".",
3217 : : name),
3218 : : errhint("Start the standby associated with the replication slot \"%s\", or amend parameter \"%s\".",
3219 : : name, "synchronized_standby_slots"));
3220 : :
3221 : : /* Continue if the current slot hasn't caught up. */
3222 : 13 : break;
3223 : : }
3224 : :
3225 [ - + ]: 7 : Assert(restart_lsn >= wait_for_lsn);
3226 : :
180 alvherre@kurilemu.de 3227 [ - + - - ]:GNC 7 : if (!XLogRecPtrIsValid(min_restart_lsn) ||
3228 : : min_restart_lsn > restart_lsn)
788 akapila@postgresql.o 3229 :CBC 7 : min_restart_lsn = restart_lsn;
3230 : :
3231 : 7 : caught_up_slot_num++;
3232 : :
3233 : 7 : name += strlen(name) + 1;
3234 : : }
3235 : :
3236 : 20 : LWLockRelease(ReplicationSlotControlLock);
3237 : :
3238 : : /*
3239 : : * Return false if not all the standbys have caught up to the specified
3240 : : * WAL location.
3241 : : */
673 3242 [ + + ]: 20 : if (caught_up_slot_num != synchronized_standby_slots_config->nslotnames)
788 3243 : 13 : return false;
3244 : :
3245 : : /* The ss_oldest_flush_lsn must not retreat. */
180 alvherre@kurilemu.de 3246 [ + + - + ]:GNC 7 : Assert(!XLogRecPtrIsValid(ss_oldest_flush_lsn) ||
3247 : : min_restart_lsn >= ss_oldest_flush_lsn);
3248 : :
788 akapila@postgresql.o 3249 :CBC 7 : ss_oldest_flush_lsn = min_restart_lsn;
3250 : :
3251 : 7 : return true;
3252 : : }
3253 : :
3254 : : /*
3255 : : * Wait for physical standbys to confirm receiving the given lsn.
3256 : : *
3257 : : * Used by logical decoding SQL functions. It waits for physical standbys
3258 : : * corresponding to the physical slots specified in the synchronized_standby_slots GUC.
3259 : : */
3260 : : void
3261 : 234 : WaitForStandbyConfirmation(XLogRecPtr wait_for_lsn)
3262 : : {
3263 : : /*
3264 : : * Don't need to wait for the standby to catch up if the current acquired
3265 : : * slot is not a logical failover slot, or there is no value in
3266 : : * synchronized_standby_slots.
3267 : : */
673 3268 [ + + + + ]: 234 : if (!MyReplicationSlot->data.failover || !synchronized_standby_slots_config)
788 3269 : 233 : return;
3270 : :
3271 : 1 : ConditionVariablePrepareToSleep(&WalSndCtl->wal_confirm_rcv_cv);
3272 : :
3273 : : for (;;)
3274 : : {
3275 [ - + ]: 2 : CHECK_FOR_INTERRUPTS();
3276 : :
3277 [ + + ]: 2 : if (ConfigReloadPending)
3278 : : {
3279 : 1 : ConfigReloadPending = false;
3280 : 1 : ProcessConfigFile(PGC_SIGHUP);
3281 : : }
3282 : :
3283 : : /* Exit if done waiting for every slot. */
3284 [ + + ]: 2 : if (StandbySlotsHaveCaughtup(wait_for_lsn, WARNING))
3285 : 1 : break;
3286 : :
3287 : : /*
3288 : : * Wait for the slots in the synchronized_standby_slots to catch up,
3289 : : * but use a timeout (1s) so we can also check if the
3290 : : * synchronized_standby_slots has been changed.
3291 : : */
3292 : 1 : ConditionVariableTimedSleep(&WalSndCtl->wal_confirm_rcv_cv, 1000,
3293 : : WAIT_EVENT_WAIT_FOR_STANDBY_CONFIRMATION);
3294 : : }
3295 : :
3296 : 1 : ConditionVariableCancelSleep();
3297 : : }
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