Disabling multicast may be useful if there is a firewall between clients, application servers or mediation servers that must discover each other. (See also Configuring the Cluster’s Multicast Address.) Application-to-mediation server communication does not use multicast, although mediation-to-application server does, unless disabled.
To disable multicast communication between application and mediation servers, define the property oware.application.servers in the installedprops/medserver/lib/installed.properties file and the property should point to the application server ip address and should be in the following format:
oware.application.servers=<application server ip address>
If the mediation server is communicating to a cluster of application servers then the value should define all the application servers separated by a comma For example:
oware.application.servers=<application server A ip address>,<application server B ip address>
Define this property on all mediation servers.
This configuration change is only for application and mediation server communication. The mediation servers in a cluster still use multicast between themselves. If you use oware.application.servers, you must (comma-separated) list all available servers wherever you use it to bypass multicast.
The context URL is also required when clients are behind firewall and wants to communicate to application server.
If you make a mistake in installing portions of your cluster, remember you must either re-source the Oware environment, or delete all files in oware/temp (and restart the process in question) before changes can be effective.
Multicast is still required between the cluster mediation servers, or application servers in a cluster unless you follow the instructions in the next section.