[pgpool-general: 1904] Re: ERROR: canceling statement due to conflict with recovery

[Tatsuo Ishii]

> Hi folks,
> 
> I have a PgPool-II solution made up of:
> 
>  - Two PgPool-II servers set up in HA mode, and
>  - Three PGSQL DB Servers using streaming replication (one primary, one
> synchronous streaming slave, and one asynchronous streaming slave).
> 
> Occasionally, when I have a fairly large query, I get the following
> error:
> 
> 	psql:query.sql:5: ERROR:  canceling statement due to conflict
> with recovery
> 
> Is this more related to the streaming replication in Postgres,

This.

> or does
> PgPoll-II have a hand to play in this (I'm guessing that using read-only
> slaves via the load balancing is the main reason for the problem)?
> 
> I've tried increasing 'max_standby_streaming_delay' to five minutes
> (should I increase this further? How much further?).
> 
> Has anyone else had this experience, and have any suggestions on how to
> alleviate the problem?

Please see our FAQ regarding the topic:
http://www.pgpool.net/mediawiki/index.php/FAQ#I_see_standby_servers_go_down_status_in_steaming_replication_mode_and_see_PostgreSQL_messages_.22terminating_connection_due_to_conflict.22_Why.3F
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese: http://www.sraoss.co.jp