Enhanced JGroups configuration

Infinispan now comes with two pre-declared stacks: tcp and udp. Using them is as simple as just referencing their names in the <transport> element.

Inlining a stack means you can put the JGroups configuration inside the Infinispan one as follows:

You can use the full JGroups schema, and by using XML namespaces you get full validation.

Most of the time you want to reuse one of the pre-declared stacks but just override some of the parameters (e.g. discovery) to suit your environment. The following example creates a new tcpgossip stack which is based on the default tcp stack but replaces the discovery protocol with TCPGOSSIP:

In the above example you can see that we have enhanced the JGroups protocol declarations with two new attributes: ispn:stack.combine and ispn:stack.position which affect how and where protocol changes are applied on the parent configuration to obtain a new configuration. stack.combine can be one of COMBINE (the default, possibly overriding any specified attributes), REPLACE (which completely replaces the protocol and resets all attributes), REMOVE (removes the protocol) and INSERT_AFTER (which places this protocol in the stack immediately after the protocol specified by stack.position).

The inline configuration really shows its usefulness in cross-site configurations. In fact, the JGroups stack declaration has been extended with a special element which replaces the need for a separate relay XML file and can reference other stacks just by name. The following configuration uses the default udp stack for the local cluster transport and uses the default tcp stack for connecting to a remote site:

Having the entire configuration in a single place greatly simplifies management. Of course you can combine all of the above features to obtain the configuration you need for your environment. You can find more details and examples in the documentation. Enjoy ! Tristan