* If true, PoolCluster will attempt to reconnect when connection fails. (Default: true)
* If connection fails, node's errorCount increases.
* When errorCount is greater than removeNodeErrorCount, remove a node in the PoolCluster. (Default: 5)
* If connection fails, specifies the number of milliseconds before another connection attempt will be made.
* If set to 0, then node will be removed instead and never re-used. (Default: 0)
* Determines how slaves are selected:
* RR: Select one alternately (Round-Robin).
* RANDOM: Select the node by random function.
* ORDER: Select the first node available unconditionally.