We moved over to Postgres from MySQL at the beginning of this academic year and have been mostly quite happy with performance. However, we've recently experienced a few occasions when some of the application servers have been having issues getting hold of the database. We run Postgres with PGpool with 100 connections, which generally seems to work well, except yesterday when we got the following error:
[Thu Nov 23 14:28:48.595788 2017] [:error] [pid 35247] [client 10.91.0.224:24593] PHP Warning: pg_connect(): Unable to connect to PostgreSQL server: FATAL: remaining connection slots are reserved for non-replication superuser connections in /moodle/lib/dml/pgsql_native_moodle_database.php on line 170, referer: http://moodle.port.ac.uk/mod/book/view.php?id=191648&chapterid=42145
'dbpersist' => 0Presumably this should be 1 or true in order to make the most of our PG pooling? We're also looking at moving to PG Bouncer in order to increase efficiency, but presumably the same config would be necessary?
Any advice much appreciated!