https://community.cloudera.com/t5/Support-Questions/Hbase-Master-Failover/m-p/118770#M81553 <P> Please read <A href="http://hbase.apache.org/book.html#architecture.master">http://hbase.apache.org/book.html#architecture.master</A> and <A href="http://hbase.apache.org/book.html#regionserver.arch.">http://hbase.apache.org/book.html#architecture.master</A>. It sounds like your interpretation on what the HBase master does is very wrong. The HBase master is *not* involved with data access requests (scans in the shell).</P><P> The verb "fail" means that when the process either stops or crashes for some reason. Sometimes processes can pause, yet recover. Part of this relates to the timeout in holding the ZooKeeper lock for distributed mutual exclusion between multiple Master processes. By default, that timeout is 30-60seconds at worst.</P> Thu, 23 Feb 2017 05:53:49 GMT elserj 2017-02-23T05:53:49Z