The c3po connection pool as been a source of issues for some time. It is not stable under heavy load, broken connections can not recover and the code base is very old and not under active development anymore.
For some time OpenOLAT supports container managed data source configuration. The goal is to make this more visible in the configuration documentation (olat.properties) and to mark the local code as deprecated.
The c3p0 connection pool will eventually be removed in future releases