koji-hub, event MPM, and postgres max_connections on el8
by Ken Dreyer
The default RHEL 7 and 8 postgresql.conf ships with "max_connections = 100".
RHEL 7's httpd uses the prefork MPM by default, and RHEL 8's httpd
uses the event MPM by default instead.
It seems that RHEL 8 opens many more simultaneous connections to the
database, and it's very easy to hit PostgreSQL's 100 max_connections
limit. In my tests, it's possible to get ServerOffline errors with
just one or two clients. For example, running kojira with kojiweb will
hit ServerOffline.
When I bump postgresql.conf to "max_connections = 500" I cannot reach
the limit on el8.
Before we tell users to bump this number in the Server HowTo guide,
I'm wondering if there is a better way to improve this in Koji's code.
https://wiki.postgresql.org/wiki/Number_Of_Database_Connections
recommends connection pooling instead of opening more connections, but
I don't know how to implement this.
- Ken
3 years, 6 months
