Modify the Operational Override File

Each Coherence cluster uses an operational override file, coh_operational_override.xml, to modify the out-of-box default cluster configuration. Modify this file to include the configuration information of the new compute instance(s) created.

You must also update all the other operational override files in your cluster to reflect the new Well Known Addresses (WKA) list. The list of WKA addresses should be the same for every cluster member to ensure that different cluster members do not operate independently from the rest of the cluster. To understand how to use Well Known Addresses, see Using Well Known Addresses in Developing Applications with Oracle Coherence.

After the stack is created and the cluster is instantiated:

1. Click the navigation menu, select Compute, and then select Instances.
2. Click the name of your compute instance(s).
3. From the Instance Details page, note the private IP address of your new compute instance(s).
4. Open the coh_operational_override.xml file that you had saved earlier, and add an entry for the IP address of the new node(s) in the <address> element as shown in the sample file. In this example file, we add an entry for a single node with the private IP address 10.0.3.4.

   <?xml version='1.0'?>
    
   <!--
   This operational configuration override file is set up for use with Coherence in
   a production mode.
   -->
   <coherence xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xmlns="http://xmlns.oracle.com/coherence/coherence-operational-config"
     xsi:schemaLocation="http://xmlns.oracle.com/coherence/coherence-operational-config coherence-operational-config.xsd">
    
     <cluster-config>
       <unicast-listener>
         <well-known-addresses>
           <socket-address id="1"><address>10.0.3.2</address><port>7574</port></socket-address>
           <socket-address id="2"><address>10.0.3.3</address><port>7574</port></socket-address>
           <socket-address id="3"><address>10.0.3.4</address><port>7574</port></socket-address>
         </well-known-addresses>
       </unicast-listener>
     </cluster-config>
   </coherence>

   Note:

   For each node, ensure that you specify a unique id attribute for each socket-address element. If you have changed the value of the cluster port from the default value 7574, then you must specify the new value for the port in this file.

5. Update each override file for every node in your cluster to reflect the new Well Known Addresses (WKA) list:
   1. Using SSH, log in to the public IP address of the node as the opc user. Then, switch to the oracle user by running the sudo su - oracle command.
   2. Open the coh_operational_override.xml file located in /opt/usr/local/etc/.
   3. Replace the content of this file with the content of the sample file above that contains your new IP(s) in the WKA list.
   4. Type exit at the shell prompt to return to the opc user.
   Repeat these steps for all the nodes in your cluster.
6. Restart cluster services by running the following commands:

   sudo systemctl stop [e-mail]

   sudo systemctl start [e-mail]

   Note:

   Replace default-cluster with your cluster name.