Hello I am sending this to the mailing list in case other people in the future have this problem
I had been seeing this error: java.nio.channels.CancelledKeyException at gnu.java.nio.SelectionKeyImpl.readyOps(libgcj.so.10) at org.apache.zookeeper.server.NIOServerCnxnFactory.run(NIOServerCnxnFactory.java:187) at java.lang.Thread.run(libgcj.so.10) and it was causing writes to be slow After some digging I found it was because I was using an outdated version of java: upgrading from 1.5 to 1.7 fixed this (relevant xkcd: http://xkcd.com/979/ )
