static void XLogFileClose(void);
static void PreallocXlogFiles(XLogRecPtr endptr);
static void RemoveOldXlogFiles(XLogSegNo segno, XLogRecPtr PriorRedoPtr, XLogRecPtr endptr);
+static void RemoveXlogFile(const char *segname, XLogRecPtr PriorRedoPtr, XLogRecPtr endptr);
static void UpdateLastRemovedPtr(char *filename);
static void ValidateXLOGDirectoryStructure(void);
static void CleanupBackupHistory(void);
}
/*
- * Recycle or remove all log files older or equal to passed segno
+ * Recycle or remove all log files older or equal to passed segno.
*
* endptr is current (or recent) end of xlog, and PriorRedoRecPtr is the
* redo pointer of the previous checkpoint. These are used to determine
static void
RemoveOldXlogFiles(XLogSegNo segno, XLogRecPtr PriorRedoPtr, XLogRecPtr endptr)
{
- XLogSegNo endlogSegNo;
- XLogSegNo recycleSegNo;
DIR *xldir;
struct dirent *xlde;
char lastoff[MAXFNAMELEN];
- char path[MAXPGPATH];
-
-#ifdef WIN32
- char newpath[MAXPGPATH];
-#endif
- struct stat statbuf;
-
- /*
- * Initialize info about where to try to recycle to.
- */
- XLByteToPrevSeg(endptr, endlogSegNo);
- recycleSegNo = XLOGfileslop(PriorRedoPtr);
xldir = AllocateDir(XLOGDIR);
if (xldir == NULL)
while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
{
+ /* Ignore files that are not XLOG segments */
+ if (strlen(xlde->d_name) != 24 ||
+ strspn(xlde->d_name, "0123456789ABCDEF") != 24)
+ continue;
+
/*
* We ignore the timeline part of the XLOG segment identifiers in
* deciding whether a segment is still needed. This ensures that we
* We use the alphanumeric sorting property of the filenames to decide
* which ones are earlier than the lastoff segment.
*/
- if (strlen(xlde->d_name) == 24 &&
- strspn(xlde->d_name, "0123456789ABCDEF") == 24 &&
- strcmp(xlde->d_name + 8, lastoff + 8) <= 0)
+ if (strcmp(xlde->d_name + 8, lastoff + 8) <= 0)
{
if (XLogArchiveCheckDone(xlde->d_name))
{
- snprintf(path, MAXPGPATH, XLOGDIR "/%s", xlde->d_name);
-
/* Update the last removed location in shared memory first */
UpdateLastRemovedPtr(xlde->d_name);
- /*
- * Before deleting the file, see if it can be recycled as a
- * future log segment. Only recycle normal files, pg_standby
- * for example can create symbolic links pointing to a
- * separate archive directory.
- */
- if (endlogSegNo <= recycleSegNo &&
- lstat(path, &statbuf) == 0 && S_ISREG(statbuf.st_mode) &&
- InstallXLogFileSegment(&endlogSegNo, path,
- true, recycleSegNo, true))
- {
- ereport(DEBUG2,
- (errmsg("recycled transaction log file \"%s\"",
- xlde->d_name)));
- CheckpointStats.ckpt_segs_recycled++;
- /* Needn't recheck that slot on future iterations */
- endlogSegNo++;
- }
- else
- {
- /* No need for any more future segments... */
- int rc;
+ RemoveXlogFile(xlde->d_name, PriorRedoPtr, endptr);
+ }
+ }
+ }
+
+ FreeDir(xldir);
+}
+
+/*
+ * Remove WAL files that are not part of the given timeline's history.
+ *
+ * This is called during recovery, whenever we switch to follow a new
+ * timeline, and at the end of recovery when we create a new timeline. We
+ * wouldn't otherwise care about extra WAL files lying in pg_xlog, but they
+ * might be leftover pre-allocated or recycled WAL segments on the old timeline
+ * that we haven't used yet, and contain garbage. If we just leave them in
+ * pg_xlog, they will eventually be archived, and we can't let that happen.
+ * Files that belong to our timeline history are valid, because we have
+ * successfully replayed them, but from others we can't be sure.
+ *
+ * 'switchpoint' is the current point in WAL where we switch to new timeline,
+ * and 'newTLI' is the new timeline we switch to.
+ */
+static void
+RemoveNonParentXlogFiles(XLogRecPtr switchpoint, TimeLineID newTLI)
+{
+ DIR *xldir;
+ struct dirent *xlde;
+ char switchseg[MAXFNAMELEN];
+ XLogSegNo endLogSegNo;
+
+ XLByteToPrevSeg(switchpoint, endLogSegNo);
+
+ xldir = AllocateDir(XLOGDIR);
+ if (xldir == NULL)
+ ereport(ERROR,
+ (errcode_for_file_access(),
+ errmsg("could not open transaction log directory \"%s\": %m",
+ XLOGDIR)));
- ereport(DEBUG2,
- (errmsg("removing transaction log file \"%s\"",
- xlde->d_name)));
+ /*
+ * Construct a filename of the last segment to be kept.
+ */
+ XLogFileName(switchseg, newTLI, endLogSegNo);
+
+ elog(DEBUG2, "attempting to remove WAL segments newer than log file %s",
+ switchseg);
+ while ((xlde = ReadDir(xldir, XLOGDIR)) != NULL)
+ {
+ /* Ignore files that are not XLOG segments */
+ if (strlen(xlde->d_name) != 24 ||
+ strspn(xlde->d_name, "0123456789ABCDEF") != 24)
+ continue;
+
+ /*
+ * Remove files that are on a timeline older than the new one we're
+ * switching to, but with a segment number >= the first segment on
+ * the new timeline.
+ */
+ if (strncmp(xlde->d_name, switchseg, 8) < 0 &&
+ strcmp(xlde->d_name + 8, switchseg + 8) > 0)
+ {
+ /*
+ * If the file has already been marked as .ready, however, don't
+ * remove it yet. It should be OK to remove it - files that are
+ * not part of our timeline history are not required for recovery
+ * - but seems safer to let them be archived and removed later.
+ */
+ if (!XLogArchiveIsReady(xlde->d_name))
+ RemoveXlogFile(xlde->d_name, InvalidXLogRecPtr, switchpoint);
+ }
+ }
+
+ FreeDir(xldir);
+}
+
+/*
+ * Recycle or remove a log file that's no longer needed.
+ *
+ * endptr is current (or recent) end of xlog, and PriorRedoRecPtr is the
+ * redo pointer of the previous checkpoint. These are used to determine
+ * whether we want to recycle rather than delete no-longer-wanted log files.
+ * If PriorRedoRecPtr is not known, pass invalid, and the function will
+ * recycle, somewhat arbitrarily, 10 future segments.
+ */
+static void
+RemoveXlogFile(const char *segname, XLogRecPtr PriorRedoPtr, XLogRecPtr endptr)
+{
+ char path[MAXPGPATH];
#ifdef WIN32
+ char newpath[MAXPGPATH];
+#endif
+ struct stat statbuf;
+ XLogSegNo endlogSegNo;
+ XLogSegNo recycleSegNo;
- /*
- * On Windows, if another process (e.g another backend)
- * holds the file open in FILE_SHARE_DELETE mode, unlink
- * will succeed, but the file will still show up in
- * directory listing until the last handle is closed. To
- * avoid confusing the lingering deleted file for a live
- * WAL file that needs to be archived, rename it before
- * deleting it.
- *
- * If another process holds the file open without
- * FILE_SHARE_DELETE flag, rename will fail. We'll try
- * again at the next checkpoint.
- */
- snprintf(newpath, MAXPGPATH, "%s.deleted", path);
- if (rename(path, newpath) != 0)
- {
- ereport(LOG,
- (errcode_for_file_access(),
- errmsg("could not rename old transaction log file \"%s\": %m",
- path)));
- continue;
- }
- rc = unlink(newpath);
+ /*
+ * Initialize info about where to try to recycle to.
+ */
+ XLByteToPrevSeg(endptr, endlogSegNo);
+ if (PriorRedoPtr == InvalidXLogRecPtr)
+ recycleSegNo = endlogSegNo + 10;
+ else
+ recycleSegNo = XLOGfileslop(PriorRedoPtr);
+
+ snprintf(path, MAXPGPATH, XLOGDIR "/%s", segname);
+
+ /*
+ * Before deleting the file, see if it can be recycled as a future log
+ * segment. Only recycle normal files, pg_standby for example can create
+ * symbolic links pointing to a separate archive directory.
+ */
+ if (endlogSegNo <= recycleSegNo &&
+ lstat(path, &statbuf) == 0 && S_ISREG(statbuf.st_mode) &&
+ InstallXLogFileSegment(&endlogSegNo, path,
+ true, recycleSegNo, true))
+ {
+ ereport(DEBUG2,
+ (errmsg("recycled transaction log file \"%s\"",
+ segname)));
+ CheckpointStats.ckpt_segs_recycled++;
+ /* Needn't recheck that slot on future iterations */
+ endlogSegNo++;
+ }
+ else
+ {
+ /* No need for any more future segments... */
+ int rc;
+
+ ereport(DEBUG2,
+ (errmsg("removing transaction log file \"%s\"",
+ segname)));
+
+#ifdef WIN32
+ /*
+ * On Windows, if another process (e.g another backend) holds the file
+ * open in FILE_SHARE_DELETE mode, unlink will succeed, but the file
+ * will still show up in directory listing until the last handle is
+ * closed. To avoid confusing the lingering deleted file for a live WAL
+ * file that needs to be archived, rename it before deleting it.
+ *
+ * If another process holds the file open without FILE_SHARE_DELETE
+ * flag, rename will fail. We'll try again at the next checkpoint.
+ */
+ snprintf(newpath, MAXPGPATH, "%s.deleted", path);
+ if (rename(path, newpath) != 0)
+ {
+ ereport(LOG,
+ (errcode_for_file_access(),
+ errmsg("could not rename old transaction log file \"%s\": %m",
+ path)));
+ return;
+ }
+ rc = unlink(newpath);
#else
- rc = unlink(path);
+ rc = unlink(path);
#endif
- if (rc != 0)
- {
- ereport(LOG,
- (errcode_for_file_access(),
- errmsg("could not remove old transaction log file \"%s\": %m",
- path)));
- continue;
- }
- CheckpointStats.ckpt_segs_removed++;
- }
-
- XLogArchiveCleanup(xlde->d_name);
- }
+ if (rc != 0)
+ {
+ ereport(LOG,
+ (errcode_for_file_access(),
+ errmsg("could not remove old transaction log file \"%s\": %m",
+ path)));
+ return;
}
+ CheckpointStats.ckpt_segs_removed++;
}
- FreeDir(xldir);
+ XLogArchiveCleanup(segname);
}
/*
/* Allow read-only connections if we're consistent now */
CheckRecoveryConsistency();
- /*
- * If this record was a timeline switch, wake up any
- * walsenders to notice that we are on a new timeline.
- */
- if (switchedTLI && AllowCascadeReplication())
- WalSndWakeup();
+ /* Is this a timeline switch? */
+ if (switchedTLI)
+ {
+ /*
+ * Before we continue on the new timeline, clean up any
+ * (possibly bogus) future WAL segments on the old timeline.
+ */
+ RemoveNonParentXlogFiles(EndRecPtr, ThisTimeLineID);
+
+ /*
+ * Wake up any walsenders to notice that we are on a new
+ * timeline.
+ */
+ if (switchedTLI && AllowCascadeReplication())
+ WalSndWakeup();
+ }
/* Exit loop if we reached inclusive recovery target */
if (recoveryStopsAfter(xlogreader))
true);
}
+ /*
+ * Clean up any (possibly bogus) future WAL segments on the old timeline.
+ */
+ if (ArchiveRecoveryRequested)
+ RemoveNonParentXlogFiles(EndOfLog, ThisTimeLineID);
+
/*
* Preallocate additional log files, if wanted.
*/
projects / postgresql / commitdiff