On Tue, Nov 13, 2018 at 2:34 PM Rui DeSousa <rui@xxxxxxxxxxxxx> wrote: > > > > > On Nov 12, 2018, at 10:28 PM, Andrey Zhidenkov <andrey.zhidenkov@xxxxxxxxx> wrote: > > > > We have a few database clusters (1 master, 2 hot standbys) with > > hot_standby_feedback setting on. But I am constantly seeing query > > conflicts on standbys because dead rows on the masters are deleted by > > VACUUM. Usually I notice it shortly after VACUUM ends, because the > > replication lag on replicas is starting to increase. > > > > vacuum_defer_cleanup_age = 0. PostgreSQL version is 9.5.13. Cluster > > load is about 1500 transactions per second. > > > > Any ideas? > > > > - > > With the best regards, Andrey Zhidenkov > > > > Are these streaming replicas? The wal_streaming process on the master should show the xmin of the replicas; you can check the value from pg_stat_activity to make sure the feedback is occurring. > Yes, they are streaming replicas. Could you please tell me how to check xmin of the replica in pg_stat_activity? I didn't get the point. > Are the replicas disconnecting from the replication stream? As the would mean the xmin from the replica would no longer be in play. No, the replicas are not disconnecting. -- - With best regards, Andrey Zhidenkov
