[pgpool-general: 1903] ERROR: canceling statement due to conflict with recovery

[Andrew Bruce]

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, 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?

Kind regards,

Andy Bruce