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xlogrecovery.c
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xlogrecovery.c
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/*-------------------------------------------------------------------------
*
* xlogrecovery.c
* Functions for WAL recovery, standby mode
*
* This source file contains functions controlling WAL recovery.
* InitWalRecovery() initializes the system for crash or archive recovery,
* or standby mode, depending on configuration options and the state of
* the control file and possible backup label file. PerformWalRecovery()
* performs the actual WAL replay, calling the rmgr-specific redo routines.
* FinishWalRecovery() performs end-of-recovery checks and cleanup actions,
* and prepares information needed to initialize the WAL for writes. In
* addition to these three main functions, there are a bunch of functions
* for interrogating recovery state and controlling the recovery process.
*
*
* Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/backend/access/transam/xlogrecovery.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <ctype.h>
#include <math.h>
#include <time.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <unistd.h>
#include "access/timeline.h"
#include "access/transam.h"
#include "access/xact.h"
#include "access/xlog_internal.h"
#include "access/xlogarchive.h"
#include "access/xlogprefetcher.h"
#include "access/xlogreader.h"
#include "access/xlogrecovery.h"
#include "access/xlogutils.h"
#include "backup/basebackup.h"
#include "catalog/pg_control.h"
#include "commands/tablespace.h"
#include "common/file_utils.h"
#include "miscadmin.h"
#include "pgstat.h"
#include "postmaster/bgwriter.h"
#include "postmaster/startup.h"
#include "replication/slot.h"
#include "replication/walreceiver.h"
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/latch.h"
#include "storage/pmsignal.h"
#include "storage/proc.h"
#include "storage/procarray.h"
#include "storage/spin.h"
#include "utils/builtins.h"
#include "utils/datetime.h"
#include "utils/guc_hooks.h"
#include "utils/pg_lsn.h"
#include "utils/ps_status.h"
#include "utils/pg_rusage.h"
/* Unsupported old recovery command file names (relative to $PGDATA) */
#define RECOVERY_COMMAND_FILE "recovery.conf"
#define RECOVERY_COMMAND_DONE "recovery.done"
/*
* GUC support
*/
const struct config_enum_entry recovery_target_action_options[] = {
{"pause", RECOVERY_TARGET_ACTION_PAUSE, false},
{"promote", RECOVERY_TARGET_ACTION_PROMOTE, false},
{"shutdown", RECOVERY_TARGET_ACTION_SHUTDOWN, false},
{NULL, 0, false}
};
/* options formerly taken from recovery.conf for archive recovery */
char *recoveryRestoreCommand = NULL;
char *recoveryEndCommand = NULL;
char *archiveCleanupCommand = NULL;
RecoveryTargetType recoveryTarget = RECOVERY_TARGET_UNSET;
bool recoveryTargetInclusive = true;
int recoveryTargetAction = RECOVERY_TARGET_ACTION_PAUSE;
TransactionId recoveryTargetXid;
char *recovery_target_time_string;
TimestampTz recoveryTargetTime;
const char *recoveryTargetName;
XLogRecPtr recoveryTargetLSN;
int recovery_min_apply_delay = 0;
/* options formerly taken from recovery.conf for XLOG streaming */
char *PrimaryConnInfo = NULL;
char *PrimarySlotName = NULL;
bool wal_receiver_create_temp_slot = false;
/*
* recoveryTargetTimeLineGoal: what the user requested, if any
*
* recoveryTargetTLIRequested: numeric value of requested timeline, if constant
*
* recoveryTargetTLI: the currently understood target timeline; changes
*
* expectedTLEs: a list of TimeLineHistoryEntries for recoveryTargetTLI and
* the timelines of its known parents, newest first (so recoveryTargetTLI is
* always the first list member). Only these TLIs are expected to be seen in
* the WAL segments we read, and indeed only these TLIs will be considered as
* candidate WAL files to open at all.
*
* curFileTLI: the TLI appearing in the name of the current input WAL file.
* (This is not necessarily the same as the timeline from which we are
* replaying WAL, which StartupXLOG calls replayTLI, because we could be
* scanning data that was copied from an ancestor timeline when the current
* file was created.) During a sequential scan we do not allow this value
* to decrease.
*/
RecoveryTargetTimeLineGoal recoveryTargetTimeLineGoal = RECOVERY_TARGET_TIMELINE_LATEST;
TimeLineID recoveryTargetTLIRequested = 0;
TimeLineID recoveryTargetTLI = 0;
static List *expectedTLEs;
static TimeLineID curFileTLI;
/*
* When ArchiveRecoveryRequested is set, archive recovery was requested,
* ie. signal files were present. When InArchiveRecovery is set, we are
* currently recovering using offline XLOG archives. These variables are only
* valid in the startup process.
*
* When ArchiveRecoveryRequested is true, but InArchiveRecovery is false, we're
* currently performing crash recovery using only XLOG files in pg_wal, but
* will switch to using offline XLOG archives as soon as we reach the end of
* WAL in pg_wal.
*/
bool ArchiveRecoveryRequested = false;
bool InArchiveRecovery = false;
/*
* When StandbyModeRequested is set, standby mode was requested, i.e.
* standby.signal file was present. When StandbyMode is set, we are currently
* in standby mode. These variables are only valid in the startup process.
* They work similarly to ArchiveRecoveryRequested and InArchiveRecovery.
*/
static bool StandbyModeRequested = false;
bool StandbyMode = false;
/* was a signal file present at startup? */
static bool standby_signal_file_found = false;
static bool recovery_signal_file_found = false;
/*
* CheckPointLoc is the position of the checkpoint record that determines
* where to start the replay. It comes from the backup label file or the
* control file.
*
* RedoStartLSN is the checkpoint's REDO location, also from the backup label
* file or the control file. In standby mode, XLOG streaming usually starts
* from the position where an invalid record was found. But if we fail to
* read even the initial checkpoint record, we use the REDO location instead
* of the checkpoint location as the start position of XLOG streaming.
* Otherwise we would have to jump backwards to the REDO location after
* reading the checkpoint record, because the REDO record can precede the
* checkpoint record.
*/
static XLogRecPtr CheckPointLoc = InvalidXLogRecPtr;
static TimeLineID CheckPointTLI = 0;
static XLogRecPtr RedoStartLSN = InvalidXLogRecPtr;
static TimeLineID RedoStartTLI = 0;
/*
* Local copy of SharedHotStandbyActive variable. False actually means "not
* known, need to check the shared state".
*/
static bool LocalHotStandbyActive = false;
/*
* Local copy of SharedPromoteIsTriggered variable. False actually means "not
* known, need to check the shared state".
*/
static bool LocalPromoteIsTriggered = false;
/* Has the recovery code requested a walreceiver wakeup? */
static bool doRequestWalReceiverReply;
/* XLogReader object used to parse the WAL records */
static XLogReaderState *xlogreader = NULL;
/* XLogPrefetcher object used to consume WAL records with read-ahead */
static XLogPrefetcher *xlogprefetcher = NULL;
/* Parameters passed down from ReadRecord to the XLogPageRead callback. */
typedef struct XLogPageReadPrivate
{
int emode;
bool fetching_ckpt; /* are we fetching a checkpoint record? */
bool randAccess;
TimeLineID replayTLI;
} XLogPageReadPrivate;
/* flag to tell XLogPageRead that we have started replaying */
static bool InRedo = false;
/*
* Codes indicating where we got a WAL file from during recovery, or where
* to attempt to get one.
*/
typedef enum
{
XLOG_FROM_ANY = 0, /* request to read WAL from any source */
XLOG_FROM_ARCHIVE, /* restored using restore_command */
XLOG_FROM_PG_WAL, /* existing file in pg_wal */
XLOG_FROM_STREAM, /* streamed from primary */
} XLogSource;
/* human-readable names for XLogSources, for debugging output */
static const char *const xlogSourceNames[] = {"any", "archive", "pg_wal", "stream"};
/*
* readFile is -1 or a kernel FD for the log file segment that's currently
* open for reading. readSegNo identifies the segment. readOff is the offset
* of the page just read, readLen indicates how much of it has been read into
* readBuf, and readSource indicates where we got the currently open file from.
*
* Note: we could use Reserve/ReleaseExternalFD to track consumption of this
* FD too (like for openLogFile in xlog.c); but it doesn't currently seem
* worthwhile, since the XLOG is not read by general-purpose sessions.
*/
static int readFile = -1;
static XLogSegNo readSegNo = 0;
static uint32 readOff = 0;
static uint32 readLen = 0;
static XLogSource readSource = XLOG_FROM_ANY;
/*
* Keeps track of which source we're currently reading from. This is
* different from readSource in that this is always set, even when we don't
* currently have a WAL file open. If lastSourceFailed is set, our last
* attempt to read from currentSource failed, and we should try another source
* next.
*
* pendingWalRcvRestart is set when a config change occurs that requires a
* walreceiver restart. This is only valid in XLOG_FROM_STREAM state.
*/
static XLogSource currentSource = XLOG_FROM_ANY;
static bool lastSourceFailed = false;
static bool pendingWalRcvRestart = false;
/*
* These variables track when we last obtained some WAL data to process,
* and where we got it from. (XLogReceiptSource is initially the same as
* readSource, but readSource gets reset to zero when we don't have data
* to process right now. It is also different from currentSource, which
* also changes when we try to read from a source and fail, while
* XLogReceiptSource tracks where we last successfully read some WAL.)
*/
static TimestampTz XLogReceiptTime = 0;
static XLogSource XLogReceiptSource = XLOG_FROM_ANY;
/* Local copy of WalRcv->flushedUpto */
static XLogRecPtr flushedUpto = 0;
static TimeLineID receiveTLI = 0;
/*
* Copy of minRecoveryPoint and backupEndPoint from the control file.
*
* In order to reach consistency, we must replay the WAL up to
* minRecoveryPoint. If backupEndRequired is true, we must also reach
* backupEndPoint, or if it's invalid, an end-of-backup record corresponding
* to backupStartPoint.
*
* Note: In archive recovery, after consistency has been reached, the
* functions in xlog.c will start updating minRecoveryPoint in the control
* file. But this copy of minRecoveryPoint variable reflects the value at the
* beginning of recovery, and is *not* updated after consistency is reached.
*/
static XLogRecPtr minRecoveryPoint;
static TimeLineID minRecoveryPointTLI;
static XLogRecPtr backupStartPoint;
static XLogRecPtr backupEndPoint;
static bool backupEndRequired = false;
/*
* Have we reached a consistent database state? In crash recovery, we have
* to replay all the WAL, so reachedConsistency is never set. During archive
* recovery, the database is consistent once minRecoveryPoint is reached.
*
* Consistent state means that the system is internally consistent, all
* the WAL has been replayed up to a certain point, and importantly, there
* is no trace of later actions on disk.
*/
bool reachedConsistency = false;
/* Buffers dedicated to consistency checks of size BLCKSZ */
static char *replay_image_masked = NULL;
static char *primary_image_masked = NULL;
/*
* Shared-memory state for WAL recovery.
*/
typedef struct XLogRecoveryCtlData
{
/*
* SharedHotStandbyActive indicates if we allow hot standby queries to be
* run. Protected by info_lck.
*/
bool SharedHotStandbyActive;
/*
* SharedPromoteIsTriggered indicates if a standby promotion has been
* triggered. Protected by info_lck.
*/
bool SharedPromoteIsTriggered;
/*
* recoveryWakeupLatch is used to wake up the startup process to continue
* WAL replay, if it is waiting for WAL to arrive or promotion to be
* requested.
*
* Note that the startup process also uses another latch, its procLatch,
* to wait for recovery conflict. If we get rid of recoveryWakeupLatch for
* signaling the startup process in favor of using its procLatch, which
* comports better with possible generic signal handlers using that latch.
* But we should not do that because the startup process doesn't assume
* that it's waken up by walreceiver process or SIGHUP signal handler
* while it's waiting for recovery conflict. The separate latches,
* recoveryWakeupLatch and procLatch, should be used for inter-process
* communication for WAL replay and recovery conflict, respectively.
*/
Latch recoveryWakeupLatch;
/*
* Last record successfully replayed.
*/
XLogRecPtr lastReplayedReadRecPtr; /* start position */
XLogRecPtr lastReplayedEndRecPtr; /* end+1 position */
TimeLineID lastReplayedTLI; /* timeline */
/*
* When we're currently replaying a record, ie. in a redo function,
* replayEndRecPtr points to the end+1 of the record being replayed,
* otherwise it's equal to lastReplayedEndRecPtr.
*/
XLogRecPtr replayEndRecPtr;
TimeLineID replayEndTLI;
/* timestamp of last COMMIT/ABORT record replayed (or being replayed) */
TimestampTz recoveryLastXTime;
/*
* timestamp of when we started replaying the current chunk of WAL data,
* only relevant for replication or archive recovery
*/
TimestampTz currentChunkStartTime;
/* Recovery pause state */
RecoveryPauseState recoveryPauseState;
ConditionVariable recoveryNotPausedCV;
slock_t info_lck; /* locks shared variables shown above */
} XLogRecoveryCtlData;
static XLogRecoveryCtlData *XLogRecoveryCtl = NULL;
/*
* abortedRecPtr is the start pointer of a broken record at end of WAL when
* recovery completes; missingContrecPtr is the location of the first
* contrecord that went missing. See CreateOverwriteContrecordRecord for
* details.
*/
static XLogRecPtr abortedRecPtr;
static XLogRecPtr missingContrecPtr;
/*
* if recoveryStopsBefore/After returns true, it saves information of the stop
* point here
*/
static TransactionId recoveryStopXid;
static TimestampTz recoveryStopTime;
static XLogRecPtr recoveryStopLSN;
static char recoveryStopName[MAXFNAMELEN];
static bool recoveryStopAfter;
/* prototypes for local functions */
static void ApplyWalRecord(XLogReaderState *xlogreader, XLogRecord *record, TimeLineID *replayTLI);
static void EnableStandbyMode(void);
static void readRecoverySignalFile(void);
static void validateRecoveryParameters(void);
static bool read_backup_label(XLogRecPtr *checkPointLoc,
TimeLineID *backupLabelTLI,
bool *backupEndRequired, bool *backupFromStandby);
static bool read_tablespace_map(List **tablespaces);
static void xlogrecovery_redo(XLogReaderState *record, TimeLineID replayTLI);
static void CheckRecoveryConsistency(void);
static void rm_redo_error_callback(void *arg);
#ifdef WAL_DEBUG
static void xlog_outrec(StringInfo buf, XLogReaderState *record);
#endif
static void xlog_block_info(StringInfo buf, XLogReaderState *record);
static void checkTimeLineSwitch(XLogRecPtr lsn, TimeLineID newTLI,
TimeLineID prevTLI, TimeLineID replayTLI);
static bool getRecordTimestamp(XLogReaderState *record, TimestampTz *recordXtime);
static void verifyBackupPageConsistency(XLogReaderState *record);
static bool recoveryStopsBefore(XLogReaderState *record);
static bool recoveryStopsAfter(XLogReaderState *record);
static char *getRecoveryStopReason(void);
static void recoveryPausesHere(bool endOfRecovery);
static bool recoveryApplyDelay(XLogReaderState *record);
static void ConfirmRecoveryPaused(void);
static XLogRecord *ReadRecord(XLogPrefetcher *xlogprefetcher,
int emode, bool fetching_ckpt,
TimeLineID replayTLI);
static int XLogPageRead(XLogReaderState *xlogreader, XLogRecPtr targetPagePtr,
int reqLen, XLogRecPtr targetRecPtr, char *readBuf);
static XLogPageReadResult WaitForWALToBecomeAvailable(XLogRecPtr RecPtr,
bool randAccess,
bool fetching_ckpt,
XLogRecPtr tliRecPtr,
TimeLineID replayTLI,
XLogRecPtr replayLSN,
bool nonblocking);
static int emode_for_corrupt_record(int emode, XLogRecPtr RecPtr);
static XLogRecord *ReadCheckpointRecord(XLogPrefetcher *xlogprefetcher,
XLogRecPtr RecPtr, TimeLineID replayTLI);
static bool rescanLatestTimeLine(TimeLineID replayTLI, XLogRecPtr replayLSN);
static int XLogFileRead(XLogSegNo segno, int emode, TimeLineID tli,
XLogSource source, bool notfoundOk);
static int XLogFileReadAnyTLI(XLogSegNo segno, int emode, XLogSource source);
static bool CheckForStandbyTrigger(void);
static void SetPromoteIsTriggered(void);
static bool HotStandbyActiveInReplay(void);
static void SetCurrentChunkStartTime(TimestampTz xtime);
static void SetLatestXTime(TimestampTz xtime);
/*
* Initialization of shared memory for WAL recovery
*/
Size
XLogRecoveryShmemSize(void)
{
Size size;
/* XLogRecoveryCtl */
size = sizeof(XLogRecoveryCtlData);
return size;
}
void
XLogRecoveryShmemInit(void)
{
bool found;
XLogRecoveryCtl = (XLogRecoveryCtlData *)
ShmemInitStruct("XLOG Recovery Ctl", XLogRecoveryShmemSize(), &found);
if (found)
return;
memset(XLogRecoveryCtl, 0, sizeof(XLogRecoveryCtlData));
SpinLockInit(&XLogRecoveryCtl->info_lck);
InitSharedLatch(&XLogRecoveryCtl->recoveryWakeupLatch);
ConditionVariableInit(&XLogRecoveryCtl->recoveryNotPausedCV);
}
/*
* A thin wrapper to enable StandbyMode and do other preparatory work as
* needed.
*/
static void
EnableStandbyMode(void)
{
StandbyMode = true;
/*
* To avoid server log bloat, we don't report recovery progress in a
* standby as it will always be in recovery unless promoted. We disable
* startup progress timeout in standby mode to avoid calling
* startup_progress_timeout_handler() unnecessarily.
*/
disable_startup_progress_timeout();
}
/*
* Prepare the system for WAL recovery, if needed.
*
* This is called by StartupXLOG() which coordinates the server startup
* sequence. This function analyzes the control file and the backup label
* file, if any, and figures out whether we need to perform crash recovery or
* archive recovery, and how far we need to replay the WAL to reach a
* consistent state.
*
* This doesn't yet change the on-disk state, except for creating the symlinks
* from table space map file if any, and for fetching WAL files needed to find
* the checkpoint record. On entry, the caller has already read the control
* file into memory, and passes it as argument. This function updates it to
* reflect the recovery state, and the caller is expected to write it back to
* disk does after initializing other subsystems, but before calling
* PerformWalRecovery().
*
* This initializes some global variables like ArchiveRecoveryRequested, and
* StandbyModeRequested and InRecovery.
*/
void
InitWalRecovery(ControlFileData *ControlFile, bool *wasShutdown_ptr,
bool *haveBackupLabel_ptr, bool *haveTblspcMap_ptr)
{
XLogPageReadPrivate *private;
struct stat st;
bool wasShutdown;
XLogRecord *record;
DBState dbstate_at_startup;
bool haveTblspcMap = false;
bool haveBackupLabel = false;
CheckPoint checkPoint;
bool backupFromStandby = false;
dbstate_at_startup = ControlFile->state;
/*
* Initialize on the assumption we want to recover to the latest timeline
* that's active according to pg_control.
*/
if (ControlFile->minRecoveryPointTLI >
ControlFile->checkPointCopy.ThisTimeLineID)
recoveryTargetTLI = ControlFile->minRecoveryPointTLI;
else
recoveryTargetTLI = ControlFile->checkPointCopy.ThisTimeLineID;
/*
* Check for signal files, and if so set up state for offline recovery
*/
readRecoverySignalFile();
validateRecoveryParameters();
if (ArchiveRecoveryRequested)
{
if (StandbyModeRequested)
ereport(LOG,
(errmsg("entering standby mode")));
else if (recoveryTarget == RECOVERY_TARGET_XID)
ereport(LOG,
(errmsg("starting point-in-time recovery to XID %u",
recoveryTargetXid)));
else if (recoveryTarget == RECOVERY_TARGET_TIME)
ereport(LOG,
(errmsg("starting point-in-time recovery to %s",
timestamptz_to_str(recoveryTargetTime))));
else if (recoveryTarget == RECOVERY_TARGET_NAME)
ereport(LOG,
(errmsg("starting point-in-time recovery to \"%s\"",
recoveryTargetName)));
else if (recoveryTarget == RECOVERY_TARGET_LSN)
ereport(LOG,
(errmsg("starting point-in-time recovery to WAL location (LSN) \"%X/%X\"",
LSN_FORMAT_ARGS(recoveryTargetLSN))));
else if (recoveryTarget == RECOVERY_TARGET_IMMEDIATE)
ereport(LOG,
(errmsg("starting point-in-time recovery to earliest consistent point")));
else
ereport(LOG,
(errmsg("starting archive recovery")));
}
/*
* Take ownership of the wakeup latch if we're going to sleep during
* recovery.
*/
if (ArchiveRecoveryRequested)
OwnLatch(&XLogRecoveryCtl->recoveryWakeupLatch);
private = palloc0(sizeof(XLogPageReadPrivate));
xlogreader =
XLogReaderAllocate(wal_segment_size, NULL,
XL_ROUTINE(.page_read = &XLogPageRead,
.segment_open = NULL,
.segment_close = wal_segment_close),
private);
if (!xlogreader)
ereport(ERROR,
(errcode(ERRCODE_OUT_OF_MEMORY),
errmsg("out of memory"),
errdetail("Failed while allocating a WAL reading processor.")));
xlogreader->system_identifier = ControlFile->system_identifier;
/*
* Set the WAL decode buffer size. This limits how far ahead we can read
* in the WAL.
*/
XLogReaderSetDecodeBuffer(xlogreader, NULL, wal_decode_buffer_size);
/* Create a WAL prefetcher. */
xlogprefetcher = XLogPrefetcherAllocate(xlogreader);
/*
* Allocate two page buffers dedicated to WAL consistency checks. We do
* it this way, rather than just making static arrays, for two reasons:
* (1) no need to waste the storage in most instantiations of the backend;
* (2) a static char array isn't guaranteed to have any particular
* alignment, whereas palloc() will provide MAXALIGN'd storage.
*/
replay_image_masked = (char *) palloc(BLCKSZ);
primary_image_masked = (char *) palloc(BLCKSZ);
if (read_backup_label(&CheckPointLoc, &CheckPointTLI, &backupEndRequired,
&backupFromStandby))
{
List *tablespaces = NIL;
/*
* Archive recovery was requested, and thanks to the backup label
* file, we know how far we need to replay to reach consistency. Enter
* archive recovery directly.
*/
InArchiveRecovery = true;
if (StandbyModeRequested)
EnableStandbyMode();
/*
* When a backup_label file is present, we want to roll forward from
* the checkpoint it identifies, rather than using pg_control.
*/
record = ReadCheckpointRecord(xlogprefetcher, CheckPointLoc,
CheckPointTLI);
if (record != NULL)
{
memcpy(&checkPoint, XLogRecGetData(xlogreader), sizeof(CheckPoint));
wasShutdown = ((record->xl_info & ~XLR_INFO_MASK) == XLOG_CHECKPOINT_SHUTDOWN);
ereport(DEBUG1,
(errmsg_internal("checkpoint record is at %X/%X",
LSN_FORMAT_ARGS(CheckPointLoc))));
InRecovery = true; /* force recovery even if SHUTDOWNED */
/*
* Make sure that REDO location exists. This may not be the case
* if there was a crash during an online backup, which left a
* backup_label around that references a WAL segment that's
* already been archived.
*/
if (checkPoint.redo < CheckPointLoc)
{
XLogPrefetcherBeginRead(xlogprefetcher, checkPoint.redo);
if (!ReadRecord(xlogprefetcher, LOG, false,
checkPoint.ThisTimeLineID))
ereport(FATAL,
(errmsg("could not find redo location referenced by checkpoint record"),
errhint("If you are restoring from a backup, touch \"%s/recovery.signal\" and add required recovery options.\n"
"If you are not restoring from a backup, try removing the file \"%s/backup_label\".\n"
"Be careful: removing \"%s/backup_label\" will result in a corrupt cluster if restoring from a backup.",
DataDir, DataDir, DataDir)));
}
}
else
{
ereport(FATAL,
(errmsg("could not locate required checkpoint record"),
errhint("If you are restoring from a backup, touch \"%s/recovery.signal\" and add required recovery options.\n"
"If you are not restoring from a backup, try removing the file \"%s/backup_label\".\n"
"Be careful: removing \"%s/backup_label\" will result in a corrupt cluster if restoring from a backup.",
DataDir, DataDir, DataDir)));
wasShutdown = false; /* keep compiler quiet */
}
/* Read the tablespace_map file if present and create symlinks. */
if (read_tablespace_map(&tablespaces))
{
ListCell *lc;
foreach(lc, tablespaces)
{
tablespaceinfo *ti = lfirst(lc);
char *linkloc;
linkloc = psprintf("pg_tblspc/%u", ti->oid);
/*
* Remove the existing symlink if any and Create the symlink
* under PGDATA.
*/
remove_tablespace_symlink(linkloc);
if (symlink(ti->path, linkloc) < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not create symbolic link \"%s\": %m",
linkloc)));
pfree(ti->path);
pfree(ti);
}
/* tell the caller to delete it later */
haveTblspcMap = true;
}
/* tell the caller to delete it later */
haveBackupLabel = true;
}
else
{
/*
* If tablespace_map file is present without backup_label file, there
* is no use of such file. There is no harm in retaining it, but it
* is better to get rid of the map file so that we don't have any
* redundant file in data directory and it will avoid any sort of
* confusion. It seems prudent though to just rename the file out of
* the way rather than delete it completely, also we ignore any error
* that occurs in rename operation as even if map file is present
* without backup_label file, it is harmless.
*/
if (stat(TABLESPACE_MAP, &st) == 0)
{
unlink(TABLESPACE_MAP_OLD);
if (durable_rename(TABLESPACE_MAP, TABLESPACE_MAP_OLD, DEBUG1) == 0)
ereport(LOG,
(errmsg("ignoring file \"%s\" because no file \"%s\" exists",
TABLESPACE_MAP, BACKUP_LABEL_FILE),
errdetail("File \"%s\" was renamed to \"%s\".",
TABLESPACE_MAP, TABLESPACE_MAP_OLD)));
else
ereport(LOG,
(errmsg("ignoring file \"%s\" because no file \"%s\" exists",
TABLESPACE_MAP, BACKUP_LABEL_FILE),
errdetail("Could not rename file \"%s\" to \"%s\": %m.",
TABLESPACE_MAP, TABLESPACE_MAP_OLD)));
}
/*
* It's possible that archive recovery was requested, but we don't
* know how far we need to replay the WAL before we reach consistency.
* This can happen for example if a base backup is taken from a
* running server using an atomic filesystem snapshot, without calling
* pg_backup_start/stop. Or if you just kill a running primary server
* and put it into archive recovery by creating a recovery signal
* file.
*
* Our strategy in that case is to perform crash recovery first,
* replaying all the WAL present in pg_wal, and only enter archive
* recovery after that.
*
* But usually we already know how far we need to replay the WAL (up
* to minRecoveryPoint, up to backupEndPoint, or until we see an
* end-of-backup record), and we can enter archive recovery directly.
*/
if (ArchiveRecoveryRequested &&
(ControlFile->minRecoveryPoint != InvalidXLogRecPtr ||
ControlFile->backupEndRequired ||
ControlFile->backupEndPoint != InvalidXLogRecPtr ||
ControlFile->state == DB_SHUTDOWNED))
{
InArchiveRecovery = true;
if (StandbyModeRequested)
EnableStandbyMode();
}
/* Get the last valid checkpoint record. */
CheckPointLoc = ControlFile->checkPoint;
CheckPointTLI = ControlFile->checkPointCopy.ThisTimeLineID;
RedoStartLSN = ControlFile->checkPointCopy.redo;
RedoStartTLI = ControlFile->checkPointCopy.ThisTimeLineID;
record = ReadCheckpointRecord(xlogprefetcher, CheckPointLoc,
CheckPointTLI);
if (record != NULL)
{
ereport(DEBUG1,
(errmsg_internal("checkpoint record is at %X/%X",
LSN_FORMAT_ARGS(CheckPointLoc))));
}
else
{
/*
* We used to attempt to go back to a secondary checkpoint record
* here, but only when not in standby mode. We now just fail if we
* can't read the last checkpoint because this allows us to
* simplify processing around checkpoints.
*/
ereport(PANIC,
(errmsg("could not locate a valid checkpoint record")));
}
memcpy(&checkPoint, XLogRecGetData(xlogreader), sizeof(CheckPoint));
wasShutdown = ((record->xl_info & ~XLR_INFO_MASK) == XLOG_CHECKPOINT_SHUTDOWN);
}
/*
* If the location of the checkpoint record is not on the expected
* timeline in the history of the requested timeline, we cannot proceed:
* the backup is not part of the history of the requested timeline.
*/
Assert(expectedTLEs); /* was initialized by reading checkpoint
* record */
if (tliOfPointInHistory(CheckPointLoc, expectedTLEs) !=
CheckPointTLI)
{
XLogRecPtr switchpoint;
/*
* tliSwitchPoint will throw an error if the checkpoint's timeline is
* not in expectedTLEs at all.
*/
switchpoint = tliSwitchPoint(ControlFile->checkPointCopy.ThisTimeLineID, expectedTLEs, NULL);
ereport(FATAL,
(errmsg("requested timeline %u is not a child of this server's history",
recoveryTargetTLI),
errdetail("Latest checkpoint is at %X/%X on timeline %u, but in the history of the requested timeline, the server forked off from that timeline at %X/%X.",
LSN_FORMAT_ARGS(ControlFile->checkPoint),
ControlFile->checkPointCopy.ThisTimeLineID,
LSN_FORMAT_ARGS(switchpoint))));
}
/*
* The min recovery point should be part of the requested timeline's
* history, too.
*/
if (!XLogRecPtrIsInvalid(ControlFile->minRecoveryPoint) &&
tliOfPointInHistory(ControlFile->minRecoveryPoint - 1, expectedTLEs) !=
ControlFile->minRecoveryPointTLI)
ereport(FATAL,
(errmsg("requested timeline %u does not contain minimum recovery point %X/%X on timeline %u",
recoveryTargetTLI,
LSN_FORMAT_ARGS(ControlFile->minRecoveryPoint),
ControlFile->minRecoveryPointTLI)));
ereport(DEBUG1,
(errmsg_internal("redo record is at %X/%X; shutdown %s",
LSN_FORMAT_ARGS(checkPoint.redo),
wasShutdown ? "true" : "false")));
ereport(DEBUG1,
(errmsg_internal("next transaction ID: " UINT64_FORMAT "; next OID: %u",
U64FromFullTransactionId(checkPoint.nextXid),
checkPoint.nextOid)));
ereport(DEBUG1,
(errmsg_internal("next MultiXactId: %u; next MultiXactOffset: %u",
checkPoint.nextMulti, checkPoint.nextMultiOffset)));
ereport(DEBUG1,
(errmsg_internal("oldest unfrozen transaction ID: %u, in database %u",
checkPoint.oldestXid, checkPoint.oldestXidDB)));
ereport(DEBUG1,
(errmsg_internal("oldest MultiXactId: %u, in database %u",
checkPoint.oldestMulti, checkPoint.oldestMultiDB)));
ereport(DEBUG1,
(errmsg_internal("commit timestamp Xid oldest/newest: %u/%u",
checkPoint.oldestCommitTsXid,
checkPoint.newestCommitTsXid)));
if (!TransactionIdIsNormal(XidFromFullTransactionId(checkPoint.nextXid)))
ereport(PANIC,
(errmsg("invalid next transaction ID")));
/* sanity check */
if (checkPoint.redo > CheckPointLoc)
ereport(PANIC,
(errmsg("invalid redo in checkpoint record")));
/*
* Check whether we need to force recovery from WAL. If it appears to
* have been a clean shutdown and we did not have a recovery signal file,
* then assume no recovery needed.
*/
if (checkPoint.redo < CheckPointLoc)
{
if (wasShutdown)
ereport(PANIC,
(errmsg("invalid redo record in shutdown checkpoint")));
InRecovery = true;
}
else if (ControlFile->state != DB_SHUTDOWNED)
InRecovery = true;
else if (ArchiveRecoveryRequested)
{
/* force recovery due to presence of recovery signal file */
InRecovery = true;
}
/*
* If recovery is needed, update our in-memory copy of pg_control to show
* that we are recovering and to show the selected checkpoint as the place
* we are starting from. We also mark pg_control with any minimum recovery
* stop point obtained from a backup history file.
*
* We don't write the changes to disk yet, though. Only do that after
* initializing various subsystems.
*/
if (InRecovery)
{
if (InArchiveRecovery)
{
ControlFile->state = DB_IN_ARCHIVE_RECOVERY;
}
else
{
ereport(LOG,
(errmsg("database system was not properly shut down; "
"automatic recovery in progress")));
if (recoveryTargetTLI > ControlFile->checkPointCopy.ThisTimeLineID)
ereport(LOG,
(errmsg("crash recovery starts in timeline %u "
"and has target timeline %u",
ControlFile->checkPointCopy.ThisTimeLineID,
recoveryTargetTLI)));
ControlFile->state = DB_IN_CRASH_RECOVERY;
}
ControlFile->checkPoint = CheckPointLoc;
ControlFile->checkPointCopy = checkPoint;
if (InArchiveRecovery)
{
/* initialize minRecoveryPoint if not set yet */
if (ControlFile->minRecoveryPoint < checkPoint.redo)
{
ControlFile->minRecoveryPoint = checkPoint.redo;
ControlFile->minRecoveryPointTLI = checkPoint.ThisTimeLineID;
}
}
/*
* Set backupStartPoint if we're starting recovery from a base backup.
*
* Also set backupEndPoint and use minRecoveryPoint as the backup end
* location if we're starting recovery from a base backup which was
* taken from a standby. In this case, the database system status in
* pg_control must indicate that the database was already in recovery.
* Usually that will be DB_IN_ARCHIVE_RECOVERY but also can be
* DB_SHUTDOWNED_IN_RECOVERY if recovery previously was interrupted
* before reaching this point; e.g. because restore_command or
* primary_conninfo were faulty.
*
* Any other state indicates that the backup somehow became corrupted
* and we can't sensibly continue with recovery.
*/
if (haveBackupLabel)
{
ControlFile->backupStartPoint = checkPoint.redo;
ControlFile->backupEndRequired = backupEndRequired;
if (backupFromStandby)
{
if (dbstate_at_startup != DB_IN_ARCHIVE_RECOVERY &&
dbstate_at_startup != DB_SHUTDOWNED_IN_RECOVERY)
ereport(FATAL,
(errmsg("backup_label contains data inconsistent with control file"),
errhint("This means that the backup is corrupted and you will "
"have to use another backup for recovery.")));
ControlFile->backupEndPoint = ControlFile->minRecoveryPoint;
}
}
}
/* remember these, so that we know when we have reached consistency */
backupStartPoint = ControlFile->backupStartPoint;
backupEndRequired = ControlFile->backupEndRequired;
backupEndPoint = ControlFile->backupEndPoint;
if (InArchiveRecovery)
{
minRecoveryPoint = ControlFile->minRecoveryPoint;
minRecoveryPointTLI = ControlFile->minRecoveryPointTLI;
}
else
{
minRecoveryPoint = InvalidXLogRecPtr;
minRecoveryPointTLI = 0;
}
/*
* Start recovery assuming that the final record isn't lost.
*/
abortedRecPtr = InvalidXLogRecPtr;
missingContrecPtr = InvalidXLogRecPtr;
*wasShutdown_ptr = wasShutdown;
*haveBackupLabel_ptr = haveBackupLabel;
*haveTblspcMap_ptr = haveTblspcMap;
}
/*
* See if there are any recovery signal files and if so, set state for
* recovery.
*
* See if there is a recovery command file (recovery.conf), and if so
* throw an ERROR since as of PG12 we no longer recognize that.
*/
static void
readRecoverySignalFile(void)
{
struct stat stat_buf;
if (IsBootstrapProcessingMode())
return;
/*
* Check for old recovery API file: recovery.conf
*/
if (stat(RECOVERY_COMMAND_FILE, &stat_buf) == 0)
ereport(FATAL,
(errcode_for_file_access(),
errmsg("using recovery command file \"%s\" is not supported",