Comment 13 for bug 1512001

See a lot of these in the zookeeper logs:

2015-11-03 18:37:37,304 - WARN [NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:NIOServerCnxn@349] - caught end of stream exception
EndOfStreamException: Unable to read additional data from client sessionid 0x50ce640c7f006e, likely client has closed socket
        at org.apache.zookeeper.server.NIOServerCnxn.doIO(NIOServerCnxn.java:220)
        at org.apache.zookeeper.server.NIOServerCnxnFactory.run(NIOServerCnxnFactory.java:208)
        at java.lang.Thread.run(Thread.java:745)
2015-11-03 18:37:37,380 - WARN [SyncThread:0:FileTxnLog@321] - fsync-ing the write ahead log in SyncThread:0 took 3633ms which will adversely effect operation latency. See the ZooKeeper troubleshooting guide
2015-11-03 18:37:37,392 - ERROR [CommitProcessor:0:NIOServerCnxn@180] - Unexpected Exception:
java.nio.channels.CancelledKeyException
        at sun.nio.ch.SelectionKeyImpl.ensureValid(SelectionKeyImpl.java:73)
        at sun.nio.ch.SelectionKeyImpl.interestOps(SelectionKeyImpl.java:77)
        at org.apache.zookeeper.server.NIOServerCnxn.sendBuffer(NIOServerCnxn.java:153)
        at org.apache.zookeeper.server.NIOServerCnxn.sendResponse(NIOServerCnxn.java:1076)
        at org.apache.zookeeper.server.FinalRequestProcessor.processRequest(FinalRequestProcessor.java:404)
        at org.apache.zookeeper.server.quorum.CommitProcessor.run(CommitProcessor.java:74)