Some insights : This is not a thread issue. I'm able to reproduce the pb with only one thread pounding the server with new connection requests (ie, it gets a connection, and move it back to the pool as soon as the search is done, and the pool just close the connection).
Here is what I get : Iteration 1 Thread Thread[Thread-2,5,main] completed in 10135ms 0 1000 2000 3000 4000 ------>> Cannot get the connection... Retrying Thread[Thread-3,5,main] failed to get a connection on iteration 4363 : Cannot connect on the server, the connection is invalid It's quite systematic : after 4363 connections, it get blocked.More investigations to come.
