Pooled connections that have been idle in the pool for longer than this timeout
will be tested before they are used again, to ensure they are still live.
If this option is set too low, an additional network call will be
incurred when acquiring a connection, which causes a performance hit.
If this is set high, you may receive sessions that are backed by no longer live connections,
which will lead to exceptions in your application. Assuming the
database is running, these exceptions will go away if you retry acquiring sessions.
Hence, this parameter tunes a balance between the likelihood of your
application seeing connection problems, and performance.
You normally should not need to tune this parameter.
No connection liveliness check is done by default.
Value
0 means connections will always be tested for
validity and negative values mean connections will never be tested.