on my testing environment, i sometimes get the following exception during CI:
com.datastax.driver.core.exceptions.BusyPoolException: [vm-test-dse-cass-] Pool is busy (no available connection and the queue has reached its max size 256
i've tried to increase the pool size and connection settings on the driver but w/o any luck. moreover, no matter how i change the driver settings, eg. set poolingOptions.maxQueueSize to 1 or 512, the result is the same error "max size 256"...
1. what cause BusyPoolException?
2. how can I overcome this? are there any settings on the server side?
3. is it a bug in the driver (cassandra-driver-3.6.0)?