Route high availability group work to a different server

 

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Overview

How you route work items for a high availability resource to a different application server during runtime depends on how your application server environment is configured.

You might need to perform this task if you have to change the application server that is handling work items for a high availability resource, such as the service integration bus. For example, if a core group includes a cluster of application servers, and a messaging engine is configured for that cluster, any of the servers in that cluster can handle work items for the messaging engine. However, if the high availability group with which the messaging engine is associated is governed by a One of N policy, only one of these application servers can be active at a given point in time.

If you are using the WAS default configuration for a high availability environment, one can change the application server that is handling the work items for a high availability resource. This change can be performed as a run-time operation (the change exists only in memory) or it can be done as a permanent configuration change. To make this change a permanent configuration change, perform one of the following steps:

 

Procedure

1. Create a preferred servers list for the policy that governs the high available group. In the administrative console, one can click Show groups on the Runtime tab for your core group to determine the high availability group name for the resource that is involved in the change.

   For example, to change which server is handling the work items for the service integration bus, create a preferred servers list for the Default SIBus Policy, which is the default policy for the service integration bus high availability group.

   1. To view this administrative console page, click...

      Servers | Core groups | Core group settings | DefaultCoreGroup | Policies | Default SIBus Policy | Preferred servers

   2. Add the desired servers to the Preferred servers list.

   3. Click Save, select Synchronize changes with Nodes and then click Save again to save your changes.

   As soon as you save your changes, all work items for the service integration bus will be routed to the new preferred server.

2. Create a new static policy for the high availability group to which the resource belongs. Verify the match criteria you specify for this new policy includes at least two of the properties specified as part of that high availability group name. To determine the high availability group name for a resource, make sure the application server that is currently handling the work items for the resource is active, and then click Show groups on the Runtime tab, in the administrative console, for your core group and enter an asterisk (*) in the Group name properties field.

   For example, to move a messaging engine, create a new policy for the messaging engine high availability group that has Static as the policy type. The match criteria for this policy must include at least two of the properties that are contained in that high availability group name. The two property match will cause the new policy to be used instead of the default policy for this group.

   1. Determine the high availability group name for the messaging engine you want to move. In the administrative console, click Core groups > Core group settings > DefaultCoreGroup, and then click on the Runtime tab. Enter an asterisk (*) in the Group name properties field. A list of the high availability groups that are contained in that core group are displayed in an administrative console panel. An example of a group name that might display on this list follows

      IBM_hc=AcceptanceCluster,WSAF_SIB_BUS=SSS_Bus,WSAF_SIB_MESSAGING_ENGINE=AcceptanceCluster.000-SSS_Bus,temp_property=WSAF_TEMP,type=jms
      

   2. Create a new static policy. In the administrative console:

      1. Click...

         Core groups | Core group settings | DefaultCoreGroup | Policies | New | Static Policy | Next

      2. Enter a policy name.

      3. Enter a policy description.

      4. Default isAlive timer setting should be 0.

      5. Do not select Quorum.

      6. Click Apply to save the new policy.

      7. Under Additional Properties, select Match Criteria and specify at least two of the properties that exist in the name of the high availability group for the messaging engine. Using the preceding group name, you might specify the following two match criteria

         WSAF_SIB_MESSAGING_ENGINE=AcceptanceCluster.000-SSS_Bus type=jms
         

      8. Under Additional Properties, select Static group servers and specify the name of the application server on which you want the messaging engine to be active.

      9. Click OK and Save to save your changes.

 

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