 |
Tune PostgreSQL memory configuration
Sometimes it is a good idea to reconfigure the number of available connections and/or the poolsize for the PostgreSQL database to improve performance.
To check the current database connection and pool size settings on
on SLES:
grep POSTGRES_OPTIONS /etc/sysconfig/postgresql
on RHEL:
grep PGOPTS /etc/sysconfig/pgsql/postgresql
and on both:
grep POOL_SIZE /opt/openexchange/etc/groupware/server.conf
If you have lots of RAM it is often a good idea to allow a large number of maximum connections to share between the applications using the pool.
For example:
# grep POSTGRES_OPTIONS /etc/sysconfig/postgresql
# POSTGRES_OPTIONS="-i -B 256 -N 128"
# grep POOL_SIZE /opt/openexchange/etc/groupware/server.conf
# POOL_SIZE: 10
Means that there are 10 connections ready in the pool and 32 are allowed in total.
The following is likely to help with an installation of 30-50 users:
1. Lowering the POOL_SIZE to 5 in both
/opt/openexchange/etc/groupware/server.conf
and
/opt/openexchange/etc/webmail/server.conf
restart Open-Xchange and tomcat services
2. Increase the number of allowed connections
stop OX
stop tomcat
change POSTGRES_OPTIONS to POSTGRES_OPTIONS="-i -B 256 -N 128"
restart postgresql
restart tomcat
restart OX
This resolves also the problem:
'Verbindungshöchstgrenze für Nicht-Superuser übschritten`'
'max. connection of superuser'
How are the connections countable?
The number of the connections depends on the settings defined within the server.conf configuration files. E.g. a POOL_SIZE value of 20 within one of those files means 20 connections of the db pool within the groupware. In addition to this there a 20 connections from the webmailer and, if Outlook is used, 20 more for the WebDAV interface. After those values aren't really hard limits at the moment, the pool takes more of connections than configured.
Furthermore one Outlook user account may also use more than one connection, which depends on what the OXtender is really doing at a given moment.
