HBase connection exception

Question

I try to run HBase in a Pseudo-Distributed mode. But it doesn't work after I set hbase-site.xml.

Each time I try to run a command inside 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 set up ssh and make sure all port are correct.

Moreover, I cannot stop hbase though ./bin/stop-hbase.sh. I only get the follow output.

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

Answer 1

Pseudo-distributed means that you are running all of the processes on one machine. You need to check that all of the required processes are running:

Hadoop:

• NameNode
• DataNode
• JobTracker
• TaskTracker

Zookeeper:

• HQuorumPeer

HBase:

• HMaster
• RegionServer

You also need to ensure that your hbase-site.xml contains the correct entries for zookeeper defining the host name and the port. The HBase FAQ and Wiki are really quite good. What are you missing from there?

Answer 2

It's because the HBase documentation has you setup your HDFS settings to point to port 8020, but the Hadoop instructions configure HDFS for port 9000.

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

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