Datasource physical connection leak happens after calling flush operation in EAP 6.x

Issue

We are monitoring physical connection between JBoss and Database server by netstat command (netstat -lantp | grep <JAVA_PID> | grep <DB_PORT>). And we noticed that the datasource physical connection leak happens after calling flush operation (flush-all-connection-in-pool / flush-idle-connection-in-pool) in EAP 6.x.