Configuring clusters of DCA Index Servers

After installing multiple DCA Index Servers, you can configure them so they share data. Typically, you configure a cluster of DCA Index Servers to replicate information so if one fails, other members of the cluster have access to the same information.

DCA Index Servers are based on an Elasticsearch search engine. 

This topic includes the following sections:

To configure multiple DCA Index Servers

1. Install multiple DCA Index Servers. See Installing only the DCA Indexing Server.
   If you want to install multiple DCA Index Servers, you must repeat the process for each instance.
2. Determine which instance of the DCA Index Server functions as the master. Note the host name and IP address of the master server.
   This information is needed for the DCA Index Servers to replicate their information between themselves. Any DCA Index Server can function as the master.
3. On each DCA Index Server, repeat the following steps:
   1. Open elasticsearch.yml for editing.
      Typically, this file resides at <install_location>/portal/DCAIndexService/config/elasticsearch.yml. 

   2. Insert the following entries anywhere in the file:
      

      network.bind_host: <IP address of the local host> 
      network.host: <IP address of the local host> 
      discovery.zen.ping.unicast.hosts: ["<IP address of master instance>"]  

      Note that for the master DCA Index Server, all three entries would specify the same IP address.

   3. Save elasticsearch.yml.
   4. Restart the BMC DCA Index service.
      • (Windows):
        1. From the Windows Control Panel, select Administrative Tools > Services
        2. Start the BMC DCA Index Service 1.7.3 (DCAIndexService) service
      • (Linux): Enter the command: /etc/init.d/DCAIndexService start
   5. Repeat these steps for each DCA Index Server.
4. On the portal server, modify the bmc-config.json file to specify the hosts that function as a cluster of DCA Index Servers.
   
   1. Open the bmc-config.json file for editing.
      Typically, this file resides at <install_location>/portal/configuration/bmc-config.json.
   2. In the file, find the following line:
      "elasticssearch.hosts":"localhost" 
   3. Modify the line so it now reads:
      "elasticssearch.hosts":"<Comma-separated list of hosts>"
      where the comma-separated list identifies the hosts that function as DCA Index Servers. The list does not have to include every host in the cluster. Instead, it can list only the DCA Index Server hosts that route requests to other DCA Index Servers. 

   4. Save bmc-config.json.

5. Start the portal server:
   • (Windows): On the portal server, open the Services window, find and right-click the BladeLogic Portal service, and select Restart. 
   • (Linux): On the portal server, enter the following command: /etc/init.d/BladeLogic_Portal restart
   During startup, the required indices are created on the DCA Index Server. Those indices must be present before you can replicate the index server. 
6. Start any utility that allows you to make REST calls. 
7. Create a PUT request:

   • Target this location: <host_name_for_any_DCA_Index_Server>:<http_port>/settings
     For example, enter:
     indexserver1.mycompany.com:9200/settings


     Note

     To manage a cluster of DCA Index Servers, you must use the underlying Elasticsearch search engine. Elasticsearch requires you to open the 9200 port on the node where management is being performed. This port is not used for any direct communication between the portal server and DCA Index Servers.

     For security reasons, many organizations only enable the 9200 port when performing management. Afterwards, the port is disabled. For more information, see "Disabling or enabling HTTP traffic with the DCA Index Server" in Advanced portal configuration. 

   • In the body of the PUT request, enter the following:

     {
        "index":{
           "number_of_replicas":1
        }
     } 

     The number of replicas should equal the total number of DCA Index Servers minus one. For example, if there are two DCA Index Servers, enter a value of 1. If there are six DCA Index Servers, enter a value of 5. Entering a value like this for number of replicas ensures that information is replicated between all DCA Index Servers. 

      Click here for an example of a PUT request.

     There are many tools you can use to create a PUT request. The following example uses the cURL command line utility.

     curl -XPUT 'localhost:9200/my_index/_settings' -d '

     {

         "index" : {

             "number_of_replicas" : 1

         }

     }’ 

8. Send the PUT request.
   After sending this request to any node used as a DCA Index Server, the cluster of DCA Index Servers begins to replicate all data between themselves.
9. Confirm that replication was successful using the web-based front end for the DCA Index Server.
   1. Follow this procedure for installing the plug-in for the web-based front end. 
   2. Check the front end to confirm that the correct number of DCA Index Servers have been replicated.

Where to go next

After configuring a cluster of DCA Index Servers, you can install BladeLogic Portal Servers.

To disable an unwanted DCA Index Server, see Troubleshooting an installation or upgrade.