27.3.2. Configure Cross-Data Replication (Library Mode)

Procedure 27.2. Setting Up Cross-Datacenter Replication

1. Configure the Local Site

   Add the site element to the global element to add the local site (in this example, the local site is named LON).

   <infinispan>
      <global>
         ...
         <site local="LON" />
         ...   
      </global>
   </infinispan>
   

2. Configure JGroups for the Local Site

   Cross-site replication requires a non-default JGroups configuration. Add the transport element and set up the path to the configuration file as the configurationFile property. In this example, the JGroups configuration file is named jgroups-with-relay.xml.

   <infinispan>
      <global>
         ...
         <site local="LON" />
         <transport clusterName="default"> 
            <properties> 
                <property name="configurationFile" value="jgroups-with-relay.xml" />     
             </properties> 
         </transport> 
         ...   
      </global>
   </infinispan>
   

3. Configure the LON Cache

   Configure the cache in site LON to back up to the sites NYC and SFO:

   <infinispan>
      <global>      
         <site local="LON" />
         ...   
      </global>
      ...
      <namedCache name="lon">
         <sites>
            <backups>
               <backup site="NYC" 
   		    strategy="SYNC" 
   		    backupFailurePolicy="WARN" />
               <backup site="SFO" 
   		    strategy="ASYNC" 
   		    backupFailurePolicy="IGNORE"/>
            </backups>
         </sites>
      </namedCache>
   </infinispan>
   

4. Configure the Back Up Caches

   1. Configure the cache in site NYC to receive back up data from LON:

      <infinispan>
         <global>      
            <site local="NYC" />
            ...   
         </global>
         ...
         <namedCache name="lonBackup">
            <sites>
               <backupFor remoteSite="LON" 
      		    remoteCache="lon" />
            </sites>
         </namedCache>
      </infinispan>
      

   2. Configure the cache in site SFO to receive back up data from LON:

      <infinispan>
         <global>      
            <site local="SFO" />
            ...   
         </global>
         ...
         <namedCache name="lonBackup">
            <sites>
               <backupFor remoteSite="LON" 
      		    remoteCache="lon" />
            </sites>
         </namedCache>
      </infinispan>
      

5. Add the Contents of the Configuration File

   As a default, Red Hat JBoss Data Grid includes JGroups configuration files such as jgroups-tcp.xml and jgroups-udp.xml in the infinispan-core-{VERSION}.jar package.
   Copy the JGroups configuration to a new file (in this example, it is named jgroups-with-relay.xml) and add the provided configuration information to this file. Note that the relay.RELAY2 protocol configuration must be the last protocol in the configuration stack.

   <config> 
       ... 
       <relay.RELAY2 site="LON" 
                 config="relay.xml"
                 relay_multicasts="false" />
   </config>
   

6. Configure the relay.xml File

   Set up the relay.RELAY2 configuration in the relay.xml file. This file describes the global cluster configuration.

   <RelayConfiguration> 
       <sites> 
           <site name="LON" 
                 id="0"> 
               <bridges> 
                   <bridge config="jgroups-global.xml" 
                           name="global"/> 
                   </bridges> 
           </site>  
           <site name="NYC" 
                 id="1"> 
               <bridges> 
                   <bridge config="jgroups-global.xml" 
                           name="global"/> 
                   </bridges> 
           </site>  
           <site name="SFO" 
                 id="2"> 
               <bridges> 
                   <bridge config="jgroups-global.xml" 
                           name="global"/> 
               </bridges> 
           </site> 
       </sites> 
   </RelayConfiguration>
   

7. Configure the Global Cluster

   The file jgroups-global.xml referenced in relay.xml contains another JGroups configuration which is used for the global cluster: communication between sites.
   The global cluster configuration is usually TCP-based and uses the TCPPING protocol (instead of PING or MPING) to discover members. Copy the contents of jgroups-tcp.xml into jgroups-global.xml and add the following configuration in order to configure TCPPING:

   <config> 
       <TCP bind_port="7800" ... /> 
       <TCPPING initial_hosts="lon.hostname[7800],nyc.hostname[7800],sfo.hostname[7800]"     
                num_initial_members="3" 
                ergonomics="false" /> 
             <!-- Rest of the protocols --> 
   </config>
   

   Replace the hostnames (or IP addresses) in TCPPING.initial_hosts with those used for your site masters. The ports (7800 in this example) must match the TCP.bind_port.
   For more information about the TCPPING protocol, see Section 24.3.1.3, “Using the TCPPing Protocol”