Operating of synchronous master when no standby is available
Hello! I use Postgresql+Pacemaker+Corosync cluster with 2 Postgresql instances in synchronous replication mode. When one of the nodes is down, clients hang on INSERT operations because the primary server waits until standby confirms that it got the data, but the standby node is down. I need clients to feel no difference when they operate with a fully operational cluster or with a degraded cluster containing primary node alone. Is it possible to configure synchronous replication to operate normally when primary and replica are online, but primary no waits confirmation from replica if replica is not connected? Best regards, Sergey Cherukhin
Re: Operating of synchronous master when no standby is available
I already have rep_mode set to "sync", but the primary node switches to async mode only if the replica is shutted down correctly. When I shut down the replica by powering it off to emulate power unit failure, primary remains in sync mode until "pcs resource cleanup" is performed. I think it is possible to run resource cleanup in script on cluster alert. вт, 3 окт. 2023 г. в 05:13, MATSUO Takatoshi : > Pgsql RA has rep_mode=sync parameter. > https://wiki.clusterlabs.org/wiki/PgSQL_Replicated_Cluster > > 2023年10月2日(月) 23:48 Sergey Cherukhin : > >> Hello! >> >> I use Postgresql+Pacemaker+Corosync cluster with 2 Postgresql instances >> in synchronous replication mode. When one of the nodes is down, clients >> hang on INSERT operations because the primary server waits until standby >> confirms that it got the data, but the standby node is down. >> >> I need clients to feel no difference when they operate with a fully >> operational cluster or with a degraded cluster containing primary >> node alone. >> >> Is it possible to configure synchronous replication to operate normally >> when primary and replica are online, but primary no waits confirmation from >> replica if replica is not connected? >> >> Best regards, >> Sergey Cherukhin >> >>
Re: Operating of synchronous master when no standby is available
Thank you for your answer. вт, 3 окт. 2023 г., 17:22 MATSUO Takatoshi : > It's not normal behavior. > > Pgsql RA is developed here. > https://github.com/ClusterLabs/resource-agents/blob/main/heartbeat/pgsql > You may get better advice if you ask on this mailing list. > https://oss.clusterlabs.org/mailman/listinfo/users > > > 2023年10月3日(火) 18:03 Sergey Cherukhin : > >> I already have rep_mode set to "sync", but the primary node switches to >> async mode only if the replica is shutted down correctly. When I shut down >> the replica by powering it off to emulate power unit failure, primary >> remains in sync mode until "pcs resource cleanup" is performed. I think it >> is possible to run resource cleanup in script on cluster alert. >> >> вт, 3 окт. 2023 г. в 05:13, MATSUO Takatoshi : >> >>> Pgsql RA has rep_mode=sync parameter. >>> https://wiki.clusterlabs.org/wiki/PgSQL_Replicated_Cluster >>> >>> 2023年10月2日(月) 23:48 Sergey Cherukhin : >>> >>>> Hello! >>>> >>>> I use Postgresql+Pacemaker+Corosync cluster with 2 Postgresql instances >>>> in synchronous replication mode. When one of the nodes is down, clients >>>> hang on INSERT operations because the primary server waits until standby >>>> confirms that it got the data, but the standby node is down. >>>> >>>> I need clients to feel no difference when they operate with a fully >>>> operational cluster or with a degraded cluster containing primary >>>> node alone. >>>> >>>> Is it possible to configure synchronous replication to operate normally >>>> when primary and replica are online, but primary no waits confirmation from >>>> replica if replica is not connected? >>>> >>>> Best regards, >>>> Sergey Cherukhin >>>> >>>>
