View source for Bridge Two Infinsipan Clustered Caches with RELAY2

=External=

* RedHat JDG Manual Cross-Datacenter Replication https://access.redhat.com/documentation/en-US/Red_Hat_JBoss_Data_Grid/6.6/html/Administration_and_Configuration_Guide/chap-Set_Up_Cross-Datacenter_Replication.html

=Internal=

* [[Infinispan Configuration#Procedures|Infinispan Configuration]]
* [[JGroups Protocol RELAY2|RELAY2]]

=Relevance=

* JDG 6.6

=Procedure=

==1. JGroups Configuration==

===1.1 Declare the Bridging Cluster JGroups Stack===

Usually is TCP-based and a good name for it would be "tcp-relay":

<pre>
            <stack name="tcp-relay">
                <transport type="TCP" socket-binding="jgroups-tcp-relay"/>
                <protocol type="TCPPING">
                    <property name="initial_hosts">
                        172.31.22.188[7610],172.31.17.76[7610],172.31.27.239[7610],172.31.30.82[7610]
                    </property>
                    <property name="num_initial_members">
                        2
                    </property>
                    <property name="port_range">
                        0
                    </property>
                    <property name="timeout">
                        2000
                    </property>
                </protocol>
                <protocol type="MERGE3"/>
                <protocol type="FD_SOCK" socket-binding="jgroups-tcp-fd-relay"/>
                <protocol type="FD_ALL"/>
                <protocol type="VERIFY_SUSPECT"/>
                <protocol type="pbcast.NAKACK2">
                    <property name="use_mcast_xmit">
                        false
                    </property>
                </protocol>
                <protocol type="UNICAST3"/>
                <protocol type="pbcast.STABLE"/>
                <protocol type="pbcast.GMS"/>
                <protocol type="MFC"/>
                <protocol type="FRAG2"/>
            </stack>
</pre>

Note that the configuration of the relay JGroups stack must be identical on all nodes across all clusters that will be relaying to each other. 

The TCPPING <tt>initial_hosts</tt> value must contain addresses from all the local clusters.

The stack definition refers two new socket bindings ("jgroups-tcp-relay" and "jgroups-tcp-fd-relay") which must be different from the main JGroups stack's bindings:

<pre>
    <socket-binding-group name="standard-sockets" ...>
        ...
        <socket-binding name="jgroups-tcp" port="7600"/>
        <socket-binding name="jgroups-tcp-fd" port="57600"/>

        <socket-binding name="jgroups-tcp-relay" port="7610"/>
        <socket-binding name="jgroups-tcp-fd-relay" port="57610"/>
        ...
    </socket-binding-group>
</pre>

===1.2 Declare the RELAY2 Protocol===

Declare the RELAY2 protocol that refers to the bridging cluster JGroups stack. The RELAY2 protocol is the place [[JGroups_Protocol_RELAY2#site|the name of the local cluster (site)]] is declared. It must be placed at the top of the main stack:

<pre>
            <stack/>
                ...
                <protocol type="FRAG2"/>
                <relay site="blue">
                    <remote-site name="red" stack="tcp-relay" cluster="bridge"/>
                    <property name="relay_multicasts">false</property>
                </relay>
            </stack>
</pre>

where the "site" is the name of the local site - the local cluster that will be relaying messages via its coordinator to other "sites".

One or more <tt><remote-site></tt>s can be declared. A <tt><remote-site></tt> declaration contains:

* the site '''name''' - the name of the remote site (the other local cluster) to forward messages to.
* the '''stack''' - represents the bridging stack name which must be declared in the same jgroups subsystem declaration.
* the '''cluster''' name - the name of the bridging JGroups group. All nodes that want to bridge over the same bridging cluster must have the same name declared here.

The symmetrical declaration for the "red" site is:

<pre>
            <stack/>
                ...
                <protocol type="FRAG2"/>
                <relay site="red">
                    <remote-site name="blue" stack="tcp-relay" cluster="bridge"/>
                    <property name="relay_multicasts">false</property>
                </relay>
            </stack>
</pre>

==2. Infinispan Configuration==

===2.1 Declare The Local Clusters (Sites) a Cache Wants to Relay To===

On the "blue" site: 

<pre>
                <distributed-cache name="bridged-cache" owners="2" mode="SYNC" start="EAGER">
                    <backups>
                        <backup site="red" strategy="SYNC" />
                        <backup site="green" strategy="SYNC" />
                    </backups>
                </distributed-cache>
</pre>

===2.2 Configure the Local Cluster Transport===

Specify the cluster name for the main JGroups stack:

<pre>
            <cache-container ...>

                <transport executor="infinispan-transport" lock-timeout="60000" cluster="blue" stack="tcp"/>

            </cache-container>

</pre>

<font color=red>Why is this necessary? Why would RELAY2 care how the local cluster is named? It has its own configuration that specifies what "site" we are. </font>