Hello, We are using the 9.1 built-in streaming replication. Recently our slave nodes fell behind because of an UPDATE statement. It took about 3 minutes to execute, but it affected half a million records, hence the replication broke with the "requested WAL segment ... has already been removed" series of error messages. The WAL settings we have are: max_wal_senders = 6 wal_keep_segments = 60 max_standby_archive_delay = 300s I guess increasing the wal_keep_segments value would prevent it from happening in the future, but increase it with how much? What value would be high enough? Also we noticed some strange error message appearing shortly before and after this same statement: "LOG: out of file descriptors: Too many open files; release and retry". Could it be related somehow and what does it mean exactly? Here's an excerpt from the master DB log: May 30 12:23:09 DB1 postgres[28201]: [13-1] user=www,db=xxx LOG: out of file descriptors: Too many open files; release and retry May 30 12:23:09 DB1 postgres[28201]: [13-2] user=www,db=xxx CONTEXT: writing block 0 of relation base/2819385/2820788 May 30 12:23:09 DB1 postgres[28201]: [13-3] user=www,db=xxx STATEMENT: UPDATE May 30 12:23:09 DB1 postgres[28201]: [13-4] ^I message May 30 12:23:09 DB1 postgres[28201]: [13-5] ^I SET May 30 12:23:09 DB1 postgres[28201]: [13-6] ^I sender_has_deleted=TRUE, May 30 12:23:09 DB1 postgres[28201]: [13-7] ^I receiver_has_deleted=TRUE May 30 12:23:09 DB1 postgres[28201]: [13-8] ^I WHERE from_profile_sid=870 ... May 30 12:39:47 DB1 postgres[9053]: [2-1] user=postgres,db=[unknown] FATAL: requested WAL segment 00000001000002DE000000BD has already been removed Regards, -- Kouber Saparev -- Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
