In hbase book, It recommends the zookeeper.session.timeout is default 60s. but, the default value is configured for 18000 in Hbase-default.xml.
Should we modify the Hbase-default.xml or book ?
188.8.131.52. ZooKeeper SessionExpired events
If you wish to increase the session timeout, add the following to your hbase-site.xml to increase the timeout from the default of 60 seconds to 120 seconds.
Be aware that setting a higher timeout means that the regions served by a failed RegionServer will take at least that amount of time to be transfered to another RegionServer. For a production system serving live requests, we would instead recommend setting it lower than 1 minute and over-provision your cluster in order the lower the memory load on each machines (hence having less garbage to collect per machine).
<description>ZooKeeper session timeout.
HBase passes this to the zk quorum as suggested maximum time for a
session. See http://hadoop.apache.org/zookeeper/docs/current/zookeeperProgrammers.html#ch_zkSessions
"The client sends a requested timeout, the server responds with the
timeout that it can give the client. "