diff options
| -rw-r--r-- | src/common/controldata_utils.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/src/common/controldata_utils.c b/src/common/controldata_utils.c index 97235874662..4d1cd1ce989 100644 --- a/src/common/controldata_utils.c +++ b/src/common/controldata_utils.c @@ -56,12 +56,22 @@ get_controlfile(const char *DataDir, bool *crc_ok_p) char ControlFilePath[MAXPGPATH]; pg_crc32c crc; int r; +#ifdef FRONTEND + pg_crc32c last_crc; + int retries = 0; +#endif Assert(crc_ok_p); ControlFile = palloc_object(ControlFileData); snprintf(ControlFilePath, MAXPGPATH, "%s/global/pg_control", DataDir); +#ifdef FRONTEND + INIT_CRC32C(last_crc); + +retry: +#endif + #ifndef FRONTEND if ((fd = OpenTransientFile(ControlFilePath, O_RDONLY | PG_BINARY)) == -1) ereport(ERROR, @@ -117,6 +127,26 @@ get_controlfile(const char *DataDir, bool *crc_ok_p) *crc_ok_p = EQ_CRC32C(crc, ControlFile->crc); +#ifdef FRONTEND + + /* + * If the server was writing at the same time, it is possible that we read + * partially updated contents on some systems. If the CRC doesn't match, + * retry a limited number of times until we compute the same bad CRC twice + * in a row with a short sleep in between. Then the failure is unlikely + * to be due to a concurrent write. + */ + if (!*crc_ok_p && + (retries == 0 || !EQ_CRC32C(crc, last_crc)) && + retries < 10) + { + retries++; + last_crc = crc; + pg_usleep(10000); + goto retry; + } +#endif + /* Make sure the control file is valid byte order. */ if (ControlFile->pg_control_version % 65536 == 0 && ControlFile->pg_control_version / 65536 != 0) |