HBase Connection Exception

Question

I am trying to start HBase in pseudo-distributed mode. But this does not work after I installed hbase-site.xml.

Every time I try to run a command inside the hbase shell, I get this error:

ERROR: org.apache.hadoop.hbase.ZooKeeperConnectionException: org.apache.hadoop.hbase.ZooKeeperConnectionException: org.apache.zookeeper.KeeperException $ ConnectionLossException: KeeperErrorCode = connectionLoss for / HBase

I installed ssh and make sure all ports are correct.

Also, I cannot stop hbase, though ./bin/stop-hbase.sh . I get only output.

 stopping hbase........................................................ 

Answer 1

Pseudo-distribution means that you are executing all processes on one machine. You need to check that all necessary processes are running:

Hadoop:

• Namenode
• Datanode
• Jobtracker
• Tasktracker

Zookeeper:

• Hquorumpeer

HBase:

• Hmaster
• RegionServer

You also need to make sure your hbase-site.xml contains the correct entries for zookeeper, specifying the host name and port. The HBase and Wiki FAQs are very good. What do you miss there?

Answer 2

This is because in the HBase documentation you configured HDFS settings to point to port 8020, but Hadoop instructions configure HDFS for port 9000.

Change the hbase-site.xml settings that HBase recommends pointing to port 9000 instead:

 <property> <name>hbase.rootdir</name> <value>hdfs://localhost:9000/hbase</value> <description>The directory shared by RegionServers. </description> </property> 

Answer 3

I had a similar problem and got the same error message as above. In my case, HMaster did not work. Using

 sudo start-hbase.sh 

solved the problem.

Answer 4

I just fixed the problem by deleting the hbase.rootdir and hbase.zookeeper.property.dataDir folders. eg:

 more conf/hbase-site.xml 

gives me: hbase.rootdir File: /// somepath / HBase / TestUser / HBase hbase.zookeeper.property.dataDir / Somepath / HBase / TestUser / Zookeeper

then delete the old data:

 rm -fr /somepath/hbase/testuser/hbase mkdir -p /somepath/hbase/testuser/hbase rm -fr /somepath/hbase/testuser/zookeeper mkdir -p /somepath/hbase/testuser/zookeeper 

then run it:

 bin/start-hbase.sh 

and finally, I can connect to the local instance:

 ./bin/hbase shell