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| author | Fujii Masao <fujii@postgresql.org> | 2016-12-17 02:20:59 +0900 |
|---|---|---|
| committer | Fujii Masao <fujii@postgresql.org> | 2016-12-17 02:25:47 +0900 |
| commit | 6c75fb6b3dbeda4dac19cee8f2d5cc7f38f362ee (patch) | |
| tree | 195321964122173b062cc709963aa4aafdb81e38 /src | |
| parent | 6f734554c38811316a9d6951b4500a6d1b0b84aa (diff) | |
| download | postgresql-6c75fb6b3dbeda4dac19cee8f2d5cc7f38f362ee.tar.gz postgresql-6c75fb6b3dbeda4dac19cee8f2d5cc7f38f362ee.zip | |
Ensure that num_sync is greater than zero in synchronous_standby_names.
Previously num_sync could be set to zero and this setting caused
an assertion failure. This means that multiple synchronous standbys
code should assume that num_sync is greater than zero.
Also setting num_sync to zero is nonsense because it's basically
the configuration for synchronous replication. If users want not to
make transaction commits wait for any standbys,
synchronous_standby_names should be emptied to disable synchronous
replication instead of setting num_sync to zero.
This patch forbids users from setting num_sync to zero in
synchronous_standby_names. If zero is specified, an error will
happen during processing the parameter settings.
Back-patch to 9.6 where multiple synchronous standbys feature was added.
Patch by me. Reviewed by Tom Lane.
Discussion: <CAHGQGwHWB3izc6cXuFLh5kOcAbFXaRhhgwd-X5PeN9TEjxqXwg@mail.gmail.com>
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/replication/syncrep.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/src/backend/replication/syncrep.c b/src/backend/replication/syncrep.c index b442d061ec0..3dfff04405d 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -922,6 +922,13 @@ check_synchronous_standby_names(char **newval, void **extra, GucSource source) return false; } + if (syncrep_parse_result->num_sync <= 0) + { + GUC_check_errmsg("number of synchronous standbys (%d) must be greater than zero", + syncrep_parse_result->num_sync); + return false; + } + /* GUC extra value must be malloc'd, not palloc'd */ pconf = (SyncRepConfigData *) malloc(syncrep_parse_result->config_size); |