From: Bruce Momjian <bruce@momjian.us> Date: Thu, 17 Apr 2014 14:52:32 +0000 (-0400) Subject: docs: adjustments for streaming standbys that disconnect frequently X-Git-Tag: REL9_4_BETA1~152 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=52e757420fa98a76015c2c88432db94269f3e8f4;p=postgresql docs: adjustments for streaming standbys that disconnect frequently Document problems when disconnection causes loss of hot_standby_feedback and suggest adjusting max_standby_archive_delay and max_standby_streaming_delay. Initial patch by Marko Tiikkaja, adjustments by me --- diff --git a/doc/src/sgml/high-availability.sgml b/doc/src/sgml/high-availability.sgml index ecb51c4b1a..39d7467ddd 100644 --- a/doc/src/sgml/high-availability.sgml +++ b/doc/src/sgml/high-availability.sgml @@ -1889,9 +1889,14 @@ if (!triggered) situation will be no worse than if the standby queries were running directly on the primary server, and you are still getting the benefit of off-loading execution onto the standby. - <varname>max_standby_archive_delay</> must be kept large in this case, - because delayed WAL files might already contain entries that conflict with - the desired standby queries. + If standby servers connect and disconnect frequently, you + might want to make adjustments to handle the period when + <varname>hot_standby_feedback</> feedback is not being provided. + For example, consider increasing <varname>max_standby_archive_delay</> + so that queries are not rapidly cancelled by conflicts in WAL archive + files during disconnected periods. You should also consider increasing + <varname>max_standby_streaming_delay</> to avoid rapid cancellations + by newly-arrived streaming WAL entries after reconnection. </para> <para>