database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-10-22 14:32:25 +03:00
Code Activity

Add -c/--restore-target-wal to pg_rewind

Browse Source 
pg_rewind needs to copy from the source cluster to the target cluster a
set of relation blocks changed from the previous checkpoint where WAL
forked up to the end of WAL on the target.  Building this list of
relation blocks requires a range of WAL segments that may not be present
anymore on the target's pg_wal, causing pg_rewind to fail.  It is
possible to work around this issue by copying manually the WAL segments
needed but this may lead to some extra and actually useless work.

This commit introduces a new option allowing pg_rewind to use a
restore_command while doing the rewind by grabbing the parameter value
of restore_command from the target cluster configuration.  This allows
the rewind operation to be more reliable, so as only the WAL segments
needed by the rewind are restored from the archives.

In order to be able to do that, a new routine is added to src/common/ to
allow frontend tools to restore files from archives using an
already-built restore command.  This version is more simple than the
backend equivalent as there is no need to handle the non-recovery case.

Author: Alexey Kondratov
Reviewed-by: Andrey Borodin, Andres Freund, Alvaro Herrera, Alexander
Korotkov, Michael Paquier
Discussion: https://postgr.es/m/a3acff50-5a0d-9a2c-b3b2-ee36168955c1@postgrespro.ru
This commit is contained in:
Michael Paquier
2020-04-01 10:57:03 +09:00
parent 92d31085e9
commit a7e8ece41c
12 changed files with 360 additions and 27 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
src/include/port.h
View File

@@ -102,10 +102,11 @@ extern void pgfnames_cleanup(char **filenames);
/* Portable locale initialization (in exec.c) */
extern void set_pglocale_pgservice(const char *argv0, const char *app);
/* Portable way to find binaries (in exec.c) */
/* Portable way to find and execute binaries (in exec.c) */
extern int find_my_exec(const char *argv0, char *retpath);
extern int find_other_exec(const char *argv0, const char *target,
const char *versionstr, char *retpath);
extern char *pipe_read_line(char *cmd, char *line, int maxsize);
/* Doesn't belong here, but this is used with find_other_exec(), so... */
#define PG_BACKEND_VERSIONSTR "postgres (PostgreSQL) " PG_VERSION "\n"