How to Reduce the Number of HBase RegionServers in Zenoss Resource Manager

Applies To

• Zenoss 5.x

Summary

The appliance and default installation of Zenoss Resource Manager 5.x include a three-node Zookeeper quorum and a three-node HBase RegionServer cluster. This can use more memory than a particular installation may require. If the performance metric throughput is low enough and the operator isn’t concerned about availability, the footprint can be reduced by dropping the number of Zookeeper and RegionServer instances to one each.

Symptoms

Unnecessary resources used for Zenoss Resource Manager installation.

Procedure

1. Stop the HBase service. This also stops its child services:

   serviced service stop hbase

2. Edit the Zookeeper service  to change the default minimum number of instances from 3 to your desired number. In a shell on the Control Center master host, run the following command:

   serviced service edit zookeeper

   1. In the editor that displays, search for the section that specifies instance details. For example:

      	"Instances": 3,
      	"InstanceLimits": {
       	"Min": 3,
      "Max": 0,
      "Default": 0
         	}

   2. Change the value for “Instances” to 1
   3. Change the “Min” value under “InstanceLimits” to 1.
   4. Save the file and exit the editor.
      
      
3. Edit the RegionServer service. Follow the same procedure as for Zookeeper, specifying the different service name when opening the editor. For example:

   serviced service edit regionserver

   1. In the editor that displays, search for the section that specifies instance details. For example:

      	"Instances": 3,
      	"InstanceLimits": {
       	"Min": 3,
      "Max": 0,
      "Default": 0
         	}

   2. Change the value for “Instances” to 1.
   3. Change the “Min” value under “InstanceLimits” to 1.
   4. Save the file and exit the editor.
      
      
4. Edit the hbase-site.xml file for the HMaster service as follows:
   1. From the Control Center UI, navigate to
      Applications > Zenoss > HMaster
   2. Navigate (scroll down) to the Configuration Files table.
   3. Navigate to and highlight the entry for hbase-site.xml.
   4. Click Edit.
   5. Change the value for property hbase.zookeeper.quorum from zk1,zk2,zk3 to zk1.
   6. Change the property hbase.master.wait.on.regionservers.mintostart to 1.

      The result should resemble:

      <property>
          <name>hbase.zookeeper.quorum</name>
          <value>zk1</value>
       </property>
      
       <property>
          <name>hbase.master.wait.on.regionservers.mintostart</name>
          <value>1</value>
       </property>

5. Save and Exit the file.
6. Restart your HBase service.