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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 02:22:15 +0900 |
| commit | 93eb619cd35b8adcfe6c86e34ea45d2e8edd322b (patch) | |
| tree | 2ac7ad2e5e5ec4b1cd1124fec584660acb413e57 | |
| parent | 23c75b55aaccddea79545ffaf1cbfc9f1edeaa8c (diff) | |
| download | postgresql-93eb619cd35b8adcfe6c86e34ea45d2e8edd322b.tar.gz postgresql-93eb619cd35b8adcfe6c86e34ea45d2e8edd322b.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>
| -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 ac29f567c3b..ce2009882d9 100644 --- a/src/backend/replication/syncrep.c +++ b/src/backend/replication/syncrep.c @@ -924,6 +924,13 @@ 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); |