We are sorry for being misled by go-zookeeper's code comment. The zk client's session timeout config is millisecond rather than second as it said... It results in the probability of "session expired" much higher than expected. So we publish a new version to handle this issue.

Now default value of zk_session_timeout in config.ini is 30000, and if it is still a small number, we will regard it as second and *1000 automatically.