线上zk做配置管理，最近突然发现两个节点一直在刷下边

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)

异常，经查发现网上相关问题处理方式为：

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After some digging I found it was because I was using an outdated version 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

相关连接：

http://zookeeper-user.578899.n2.nabble.com/solution-for-java-nio-channels-CancelledKeyException-td7580505.html