Add pg_rewind --no-sync

This is an option consistent with what pg_dump and pg_basebackup provide
which is useful for leveraging the I/O effort when testing things, not
to be used in a production environment.

Author: Michael Paquier
Reviewed-by: Heikki Linnakangas
Discussion: https://postgr.es/m/20180325122607.GB3707@paquier.xyz
This commit is contained in:
Michael Paquier 2018-07-10 08:51:10 +09:00
parent 9a4059d4ff
commit 8a00b96aa9
3 changed files with 30 additions and 4 deletions

View File

@ -171,6 +171,22 @@ PostgreSQL documentation
</listitem>
</varlistentry>
<varlistentry>
<term><option>-N</option></term>
<term><option>--no-sync</option></term>
<listitem>
<para>
By default, <command>pg_rewind</command> will wait for all files
to be written safely to disk. This option causes
<command>pg_rewind</command> to return without waiting, which is
faster, but means that a subsequent operating system crash can leave
the synchronized data folder corrupt. Generally, this option is
useful for testing but should not be used when creating a production
installation.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-P</option></term>
<term><option>--progress</option></term>

View File

@ -231,7 +231,8 @@ sub run_pg_rewind
'pg_rewind',
"--debug",
"--source-pgdata=$standby_pgdata",
"--target-pgdata=$master_pgdata"
"--target-pgdata=$master_pgdata",
"--no-sync"
],
'pg_rewind local');
}
@ -243,7 +244,8 @@ sub run_pg_rewind
[
'pg_rewind', "--debug",
"--source-server", $standby_connstr,
"--target-pgdata=$master_pgdata"
"--target-pgdata=$master_pgdata",
"--no-sync"
],
'pg_rewind remote');
}

View File

@ -56,6 +56,7 @@ char *connstr_source = NULL;
bool debug = false;
bool showprogress = false;
bool dry_run = false;
bool do_sync = true;
/* Target history */
TimeLineHistoryEntry *targetHistory;
@ -71,6 +72,8 @@ usage(const char *progname)
printf(_(" --source-pgdata=DIRECTORY source data directory to synchronize with\n"));
printf(_(" --source-server=CONNSTR source server to synchronize with\n"));
printf(_(" -n, --dry-run stop before modifying anything\n"));
printf(_(" -N, --no-sync do not wait for changes to be written\n"));
printf(_(" safely to disk\n"));
printf(_(" -P, --progress write progress messages\n"));
printf(_(" --debug write a lot of debug messages\n"));
printf(_(" -V, --version output version information, then exit\n"));
@ -89,6 +92,7 @@ main(int argc, char **argv)
{"source-server", required_argument, NULL, 2},
{"version", no_argument, NULL, 'V'},
{"dry-run", no_argument, NULL, 'n'},
{"no-sync", no_argument, NULL, 'N'},
{"progress", no_argument, NULL, 'P'},
{"debug", no_argument, NULL, 3},
{NULL, 0, NULL, 0}
@ -125,7 +129,7 @@ main(int argc, char **argv)
}
}
while ((c = getopt_long(argc, argv, "D:nP", long_options, &option_index)) != -1)
while ((c = getopt_long(argc, argv, "D:nNP", long_options, &option_index)) != -1)
{
switch (c)
{
@ -141,6 +145,10 @@ main(int argc, char **argv)
dry_run = true;
break;
case 'N':
do_sync = false;
break;
case 3:
debug = true;
break;
@ -709,7 +717,7 @@ updateControlFile(ControlFileData *ControlFile)
static void
syncTargetDirectory(const char *argv0)
{
if (dry_run)
if (!do_sync || dry_run)
return;
fsync_pgdata(datadir_target, progname, PG_VERSION_NUM);