I am having a few map reduce job run against Hbase using apache phoenix using PhoenixMapReduceUtil. To launch the map reduce jobs, i use a Java program which is a long running process, that wait for triggers to launch the program. Problem is that the number of open file descriptors for the program keep on increasing over a period of time finally stopping jobs saying "too many open files". When I checked the open files listing that is getting accumulated, all are either Zookeeper connections (2181 port) or Hbase connection (16070 port). As far as launcher is alive, these connections are on. Any pointers on how to clean these connections without actually stopping the Launcher program ?