I'm in the process of upgrading a few CDH3 clusters from 0.90.2 to 0.90.4.
I noticed that after starting the 0.90.4 Master (also verified in 0.90.3), I
see this series of messages every 5 seconds in the Master log:
There are corresponding log entries in the ZooKeeper server log every 5
So the Master is connecting to ZooKeeper and then immediately disconnecting
every 5 seconds for some reason. Is this expected? I don't see any errors
on the master or region servers, and HBase appears to be functioning
normally. Should I just set the log level to WARN and not worry about it,
or is this actually a problem?