database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-27 23:21:58 +03:00
Code Activity

Prevent WAL files created by pg_basebackup -x/X from being archived again.

Browse Source 
WAL (and timeline history) files created by pg_basebackup did not
maintain the new base backup's archive status. That's currently not a
problem if the new node is used as a standby - but if that node is
promoted all still existing files can get archived again.  With a high
wal_keep_segment settings that can happen a significant time later -
which is quite confusing.

Change both the backend (for the -x/-X fetch case) and pg_basebackup
(for -X stream) itself to always mark WAL/timeline files included in
the base backup as .done. That's in line with walreceiver.c doing so.

The verbosity of the pg_basebackup changes show pretty clearly that it
needs some refactoring, but that'd result in not be backpatchable
changes.

Backpatch to 9.1 where pg_basebackup was introduced.

Discussion: 20141205002854.GE21964@awork2.anarazel.de
This commit is contained in:
Andres Freund
2015-01-03 20:51:52 +01:00
parent bb2e2ce6e2
commit f6cea45029
5 changed files with 116 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
src/backend/replication/basebackup.c
View File

@ -404,6 +404,7 @@ perform_base_backup(basebackup_options *opt, DIR *tblspcdir)
errmsg("unexpected WAL file size \"%s\"", walFiles[i])));
}
/* send the WAL file itself */
_tarWriteHeader(pathbuf, NULL, &statbuf);
while ((cnt = fread(buf, 1, Min(sizeof(buf), XLogSegSize - len), fp)) > 0)
@ -428,7 +429,17 @@ perform_base_backup(basebackup_options *opt, DIR *tblspcdir)
}
/* XLogSegSize is a multiple of 512, so no need for padding */
FreeFile(fp);
/*
* Mark file as archived, otherwise files can get archived again
* after promotion of a new node. This is in line with
* walreceiver.c always doing a XLogArchiveForceDone() after a
* complete segment.
*/
StatusFilePath(pathbuf, walFiles[i], ".done");
sendFileWithContent(pathbuf, "");
}
/*
@ -452,6 +463,10 @@ perform_base_backup(basebackup_options *opt, DIR *tblspcdir)
errmsg("could not stat file \"%s\": %m", pathbuf)));
sendFile(pathbuf, pathbuf, &statbuf, false);
/* unconditionally mark file as archived */
StatusFilePath(pathbuf, fname, ".done");
sendFileWithContent(pathbuf, "");
}
/* Send CopyDone message for the last tar file */
@ -900,6 +915,15 @@ sendDir(char *path, int basepathlen, bool sizeonly, List *tablespaces)
_tarWriteHeader(pathbuf + basepathlen + 1, NULL, &statbuf);
}
size += 512; /* Size of the header just added */
/*
* Also send archive_status directory (by hackishly reusing
* statbuf from above ...).
*/
if (!sizeonly)
_tarWriteHeader("./pg_xlog/archive_status", NULL, &statbuf);
size += 512; /* Size of the header just added */
continue; /* don't recurse into pg_xlog */
}