Please see the config parameters maxIdleTime and maxIdleTimeExcessConnections.
If you want to aggressively pare back pool size when load lightens, set a short maxIdleTimeExcessConnections
. Leave just plain maxIdleTime
fairly long, so you don't needlessly churn through Connections once your pool has hit minPoolSize
.
If you don't care so much, then just set maxIdleTime
and eventually the pool will shrink as idle Connections expire. But for reasonable values of maxIdleTime
, this will happen slowly.
If neither maxIdleTime
nor maxIdleTimeExcessConnections
(nor maxConnectionAge) are set, these values all default to zero, meaning Connections never expire, and the pool will only shrink as Connections break and fail tests.