Moving a Single-node Setup to a Minimum HA Cluster

This section explains how to move a single node that is currently operating as a single node to a minimum HA cluster together with a new node. Here you need to avoid losing the data saved in the exising single node. To  do this, follow the steps below.

1. Shutdown the nodes that is currently deployed in the standalone mode.
2. Delete all the tables that start with ANX___8 in the event store db.
3. Delete all the data in the <DAS_HOME>/repository/data directory.
4. In the <DAS_HOME>/repository/conf/analytics/local-shard-allocation-config.conf file, change the mode for all the shards from NORMAL to INIT. For more information, see Indexing Overview - Re-indexing.

5. Setup the minimum HA cluster with your existing node and the new node by following the instructions in the WSO2 Clustering Guide - Minimum High Availability Deployment for WSO2 DAS 3.1.0.

   The following are the most important configurations that you need to verify:

   • To enable clustering, the following property is set in the <DAS_HOME>/repository/conf/axis2/axis2.xml file.
     

     <clustering class="org.wso2.carbon.core.clustering.hazelcast.HazelcastClusteringAgent" enable="true">

   • To enable the HA mode, the following property should be set in the <DAS_HOME>/repository/conf/event-processor.xml file.

     <mode name="HA" enable="true">

   • To specify that there must be two workers in the cluster, the following property should be set in the <DAS_HOME>/repository/conf/analytics/spark/spark-defaults.conf file.
     

     carbon.spark.master.count 2