Curator can NOT reconnect after connection lost and session expired when the connection come up while the DNS server is not ready yet.(zookeeper connection string using domain names)

1. Add following lines to the /etc/hosts:
x.x.x.x zk1.test.com
x.x.x.x zk2.test.com
x.x.x.x zk3.test.com

2. RUN the test programme
3. shutdown the network connection to x.x.x.x
4. wait until the session expires (for example 10 min)
5. remove the added 3 lines in /etc/hosts
6. open the network connection to x.x.x.x
7. watch that curator cannot reconnect
8. add the 3 lines to /etc/hosts
9. watch that curator cannot reconnect either

The log may look like the following:
[main-SendThread(172.24.2.35:2181)][INFO ]2016-01-26 11:07:45.005 [ClientCnxn.logStartConnect] - Opening socket connection to server 172.24.2.35/172.24.2.35:2181. Will not attempt to authenticate using SASL (unknown error)
[main-SendThread(172.24.2.35:2181)][INFO ]2016-01-26 11:07:45.050 [ClientCnxn.primeConnection] - Socket connection established to 172.24.2.35/172.24.2.35:2181, initiating session
[main-EventThread][WARN ]2016-01-26 11:07:45.093 [ConnectionState.handleExpiredSession] - Session expired event received
[main-EventThread][DEBUG]2016-01-26 11:07:45.093 [ConnectionState.reset] - reset
[main-SendThread(172.24.2.35:2181)][INFO ]2016-01-26 11:07:45.093 [ClientCnxn.run] - Unable to reconnect to ZooKeeper service, session 0x1525d9593a537af has expired, closing socket connection
[main-EventThread][INFO ]2016-01-26 11:07:45.095 [ZooKeeper.<init>] - Initiating client connection, connectString=zk1.test.com:2181,zk2.test.com:2181,zk3.test.com:2181 sessionTimeout=60000 watcher=org.apache.curator.ConnectionState@7e7d611f
[main-EventThread][INFO ]2016-01-26 11:07:45.488 [ClientCnxn.run] - EventThread shut down
[main-SendThread(111.206.227.147:2181)][INFO ]2016-01-26 11:07:45.615 [ClientCnxn.logStartConnect] - Opening socket connection to server 111.206.227.147/111.206.227.147:2181. Will not attempt to authenticate using SASL (unknown error)
[Curator-ConnectionStateManager-0][DEBUG]2016-01-26 11:07:58.523 [CuratorZookeeperClient.blockUntilConnectedOrTimedOut] - blockUntilConnectedOrTimedOut() end. isConnected: false