Upgrading an existing Accumulo 1.6 CDH5 cluster to HDFS HA

by thomas.memenga on 2015-03-08

Upgrading an existing Accumulo 1.6 CDH5 cluster to HDFS HA

Theses steps are neccessary for Accumulo 1.6 after upgrading an existing CDH5 cluster to HDFS HA.

Upgrading an existing CDH5 Cluster to HDFS HA is well documented and the Cloudera Manager will guide you through the process using a wizard. But if you are running Accumulo 1.6 on that cluster, your instance will still try to access old hdfs paths like hdfs://youroldnamenodehost:8020/accumulo/… as these fully qualified paths have not been migrated by the HA upgrade wizard.

To fix this you would need to add the proper configuration values for

  * **instance.dfs.uri**
  * **instance.volumes**
  * **instance.volumes.replacements**

to the Accumulo 1.6 Service Advanced Configuration Snippet (Safety Valve) for accumulo-site.xml (Accumulo 1.6 (Service-Wide)).

(replace “newnameservicename” and “oldnamenodehostname” accordingly)

 <property>
    <name>instance.dfs.uri</name>
    <value>hdfs://newnameservicename</value>
  </property>
 <property>
    <name>instance.volumes</name>
    <value>hdfs://newnameservicename/accumulo</value>
  </property>
 <property>
    <name>instance.volumes.replacements</name>
    <value>hdfs://oldnamenodehostname:8020/accumulo hdfs://newnameservicename/accumulo</value>
 </property>

After restarting your Accumulo instance should be able to find its data on the migrated high availability HDFS.