HMaster not starting -- TableExistsException

[#1]

Hello, 

I found out that for this exception :

Unhandled exception. Starting shutdown.
org.apache.hadoop.hbase.TableExistsException: hbase:namespace
	at org.apache.hadoop.hbase.master.handler.CreateTableHandler.prepare(CreateTableHandler.java:120)
	at org.apache.hadoop.hbase.master.TableNamespaceManager.createNamespaceTable(TableNamespaceManager.java:230)
	at org.apache.hadoop.hbase.master.TableNamespaceManager.start(TableNamespaceManager.java:85)
	at org.apache.hadoop.hbase.master.HMaster.initNamespace(HMaster.java:1059)
	at org.apache.hadoop.hbase.master.HMaster.finishInitialization(HMaster.java:920)
	at org.apache.hadoop.hbase.master.HMaster.run(HMaster.java:606)
	at java.lang.Thread.run(Thread.java:744)

I need to clean the /habse in zookeper but I didn't find it. I didn't find how to remove a ZNODE, is it located in the HDFS ?

Found some clue here :

http://web.archiveorange.com/archive/v/WCpTuGEshqKoq2ZC4X3L

(For the record, I got this error after deleting all services and reinstalling them one by one).

Thanks for your help 🙂

[#2 · Accepted solution]

Hello,

You can access ZooKeeper via several methods, but the easiest is to use the 'hbase zkcli' command from one of the servers running an HBase service.  Once in the ZooKeeper CLI, you can run 'rmr /hbase' to remove the znode.

As you have found, this is a necessary step if you are removing and reinstalling HBase using the same ZooKeeper.