We just upgraded to 2.4.7 and we appear to be having performance issues.
We run 4 web servers behind an HA proxy load balancer, with a single DB machine.
The moodle data directory is mounted on the DB machine from a SAN and exposed to the front end web servers via NFS.
Following the upgrade to 2.4.7 we're finding that the DB machine starts off with a handful of connections, but this rapidly ramps up to over 500 db connections.
This then causes the whole service to fall over.
The only change introduced is the upgrade to 2.4.8 from 2.4.7+ and the addition of a new assignsubmission plugin and gradebook report.