diff options
Diffstat (limited to 'contrib')
| -rw-r--r-- | contrib/pg_standby/pg_standby.c | 115 |
1 files changed, 101 insertions, 14 deletions
diff --git a/contrib/pg_standby/pg_standby.c b/contrib/pg_standby/pg_standby.c index d7fa2a80c69..6aeca6e8f72 100644 --- a/contrib/pg_standby/pg_standby.c +++ b/contrib/pg_standby/pg_standby.c @@ -36,6 +36,8 @@ const char *progname; +int WalSegSz = -1; + /* Options and defaults */ int sleeptime = 5; /* amount of time to sleep between file checks */ int waittime = -1; /* how long we have been waiting, -1 no wait @@ -100,6 +102,10 @@ int nextWALFileType; struct stat stat_buf; +static bool SetWALFileNameForCleanup(void); +static bool SetWALSegSize(void); + + /* ===================================================================== * * Customizable section @@ -176,6 +182,35 @@ CustomizableNextWALFileReady(void) if (stat(WALFilePath, &stat_buf) == 0) { /* + * If we've not seen any WAL segments, we don't know the WAL segment + * size, which we need. If it looks like a WAL segment, determine size + * of segments for the cluster. + */ + if (WalSegSz == -1 && IsXLogFileName(nextWALFileName)) + { + if (SetWALSegSize()) + { + /* + * Successfully determined WAL segment size. Can compute + * cleanup cutoff now. + */ + need_cleanup = SetWALFileNameForCleanup(); + if (debug) + { + fprintf(stderr, + _("WAL segment size: %d \n"), WalSegSz); + fprintf(stderr, "Keep archive history: "); + + if (need_cleanup) + fprintf(stderr, "%s and later\n", + exclusiveCleanupFileName); + else + fprintf(stderr, "no cleanup required\n"); + } + } + } + + /* * If it's a backup file, return immediately. If it's a regular file * return only if it's the right size already. */ @@ -184,7 +219,7 @@ CustomizableNextWALFileReady(void) nextWALFileType = XLOG_BACKUP_LABEL; return true; } - else if (stat_buf.st_size == XLOG_SEG_SIZE) + else if (WalSegSz > 0 && stat_buf.st_size == WalSegSz) { #ifdef WIN32 @@ -204,7 +239,7 @@ CustomizableNextWALFileReady(void) /* * If still too small, wait until it is the correct size */ - if (stat_buf.st_size > XLOG_SEG_SIZE) + if (WalSegSz > 0 && stat_buf.st_size > WalSegSz) { if (debug) { @@ -218,8 +253,6 @@ CustomizableNextWALFileReady(void) return false; } -#define MaxSegmentsPerLogFile ( 0xFFFFFFFF / XLOG_SEG_SIZE ) - static void CustomizableCleanupPriorWALFiles(void) { @@ -315,6 +348,7 @@ SetWALFileNameForCleanup(void) uint32 log_diff = 0, seg_diff = 0; bool cleanup = false; + int max_segments_per_logfile = (0xFFFFFFFF / WalSegSz); if (restartWALFileName) { @@ -336,12 +370,12 @@ SetWALFileNameForCleanup(void) sscanf(nextWALFileName, "%08X%08X%08X", &tli, &log, &seg); if (tli > 0 && seg > 0) { - log_diff = keepfiles / MaxSegmentsPerLogFile; - seg_diff = keepfiles % MaxSegmentsPerLogFile; + log_diff = keepfiles / max_segments_per_logfile; + seg_diff = keepfiles % max_segments_per_logfile; if (seg_diff > seg) { log_diff++; - seg = MaxSegmentsPerLogFile - (seg_diff - seg); + seg = max_segments_per_logfile - (seg_diff - seg); } else seg -= seg_diff; @@ -365,6 +399,66 @@ SetWALFileNameForCleanup(void) } /* + * Try to set the wal segment size from the WAL file specified by WALFilePath. + * + * Return true if size could be determined, false otherwise. + */ +static bool +SetWALSegSize(void) +{ + bool ret_val = false; + int fd; + char *buf = (char *) malloc(XLOG_BLCKSZ); + + Assert(WalSegSz == -1); + + if ((fd = open(WALFilePath, O_RDWR, 0)) < 0) + { + fprintf(stderr, "%s: couldn't open WAL file \"%s\"\n", + progname, WALFilePath); + return false; + } + if (read(fd, buf, XLOG_BLCKSZ) == XLOG_BLCKSZ) + { + XLogLongPageHeader longhdr = (XLogLongPageHeader) buf; + + WalSegSz = longhdr->xlp_seg_size; + + if (IsValidWalSegSize(WalSegSz)) + { + /* successfully retrieved WAL segment size */ + ret_val = true; + } + else + fprintf(stderr, + "%s: WAL segment size must be a power of two between 1MB and 1GB, but the WAL file header specifies %d bytes\n", + progname, WalSegSz); + close(fd); + } + else + { + /* + * Don't complain loudly, this is to be expected for segments being + * created. + */ + if (errno != 0) + { + if (debug) + fprintf(stderr, "could not read file \"%s\": %s", + WALFilePath, strerror(errno)); + } + else + { + if (debug) + fprintf(stderr, "not enough data in file \"%s\"", WALFilePath); + } + } + + fflush(stderr); + return ret_val; +} + +/* * CheckForExternalTrigger() * * Is there a trigger file? Sets global 'Failover' variable to indicate @@ -708,8 +802,6 @@ main(int argc, char **argv) CustomizableInitialize(); - need_cleanup = SetWALFileNameForCleanup(); - if (debug) { fprintf(stderr, "Trigger file: %s\n", triggerPath ? triggerPath : "<not set>"); @@ -721,11 +813,6 @@ main(int argc, char **argv) fprintf(stderr, "Max wait interval: %d %s\n", maxwaittime, (maxwaittime > 0 ? "seconds" : "forever")); fprintf(stderr, "Command for restore: %s\n", restoreCommand); - fprintf(stderr, "Keep archive history: "); - if (need_cleanup) - fprintf(stderr, "%s and later\n", exclusiveCleanupFileName); - else - fprintf(stderr, "no cleanup required\n"); fflush(stderr); } |