and this actual value (from v$cpool_stats):
CONNECTION_POOL SYS_DEFAULT_CONNECTION_POOL STATUS ACTIVE MINSIZE 4 MAXSIZE 100 INCRSIZE 2 SESSION_CACHED_CURSORS 20 INACTIVITY_TIMEOUT 300 MAX_THINK_TIME 120 MAX_USE_SESSION 500000 MAX_LIFETIME_SESSION 86400
What suddenly I noticed is that num_misses = num_request.
POOL_NAME SYS_DEFAULT_CONNECTION_POOL NUM_OPEN_SERVERS 37 NUM_BUSY_SERVERS 30 NUM_AUTH_SERVERS 1 NUM_REQUESTS 93156 NUM_HITS 0 NUM_MISSES 93156 NUM_WAITS 0 WAIT_TIME 0 CLIENT_REQ_TIMEOUTS 0 NUM_AUTHENTICATIONS 2571 NUM_PURGED 0 HISTORIC_MAX 37
take a look at here:
I think you shall put your connection class and connection purity and it will be fine. About the version and the bugs, I don't think so. You can use DRCP in 11.1. But keep in mind that is good idea to patch and upgrade your database more often