Meaning of "Value was returned to the bag that was not borrowed"? about hikaricp

[brettwooldridge]

Wow, what is going on? I see com.mchange.v2.sql.filter.FilterConnection.close() in the stacktrace. That class is from the C3P0 connection pool. It is generally a bad idea to wrap one connection pool (HikariCP) inside of another (C3P0). Is it possible to remove C3P0 from the configuration?

[brettwooldridge]

Looking at the exception itself, it appears that someone is calling getConnection(), using the connection, calling close() on the Connection, then continuing to use the connection before calling close() again on the Connection. This may, or may not, be a side-effect of wrapping HikariCP inside of C3P0.

[jaredstehler]

We aren't actually using two pools; we've written a wrapper around jdbc which uses hystrix to fail over to another datasource if one is having issues. The mchange class is a simple delegating wrapper so we didn't have to implement the 50-odd methods of the JDBC connection interface.

[brettwooldridge]

I see. The core cause of the exception seems to be as stated. Some code path is closing a Connection but continuing to use it. The stacktrace provided may point to the cause or it may point to the victim.

[jaredstehler]

Thanks!