Hi, after the master has connected successfully some thousand slaves it can't connect anymore and each new slave receives FATAL ERROR (EvolutionState not created yet): java.net.SocketException: Connection reset Nevertheless long evolution runs are not the problem. Only connects (a few thousand). Any suggestions where to start digging? Greetings, Ralf P.S. Hm ... btw: the clients disconnect (brutally) by kicking them (running on a cluster with a wall-time).