Interoperate with v6.0.2 and later processes

The high availability manager supports multihomed hosts, which means that the product processes can communicate with each other even if they are running on different versions of the product. If we are running v6.0.2 and later processes that need to communicate with each other, we need to consider there are high availability manager-related issues.

Know the version levels of the processes that need to communicate with each other. If v6.0.1.2 processes exist, see Interoperating with v6.0.1.2 processes for additional considerations.

When processes are created on v6.0.2 or later nodes, the host name field in the DCS_UNICAST_ADDRESS endpoint is set to an asterisk. When we use an asterisk in the host name field, multihome support allows the high availability manager to open and accept connections using any IP address that is valid for that machine.

Special considerations are required when v6.0.2 nodes interoperate with v6.0 and v6.0.1 nodes without Fix Pack 2 (6.0.1.2), because these earlier versions do not contain high availability manager multihome support. v6.0 and v6.0.1 processes do not recognize an asterisk as a valid value in the DCS_UNICAST_ADDRESS host name field. Therefore, these processes cannot connect to v6.0.2 processes configured with an asterisk in the DCS_UNICAST_ADDRESS host name field. When v6.0.2 processes must interoperate with v6.0 or v6.0.1 processes, the DCS_UNICAST_ADDRESS for all v6.0.2 processes must be configured to use a value other than an asterisk. This configuration is done by setting the host name field in the DCS_UNICAST_ADDRESS endpoint to a host name or to a textual IP address.

• If the host is configured to use a single IP address, a string host name, for example, myhost.mydomain, is sufficient.

• If the host is configured to use multiple IP addresses, then a textual IP address, for example, 192.168.0.2, is required.

As we add v6.0.2 nodes and create servers into a mixed-release cell, set the host name field of the DCS_UNICAST_ADDRESS for all processes on the new nodes, including the node agent, to one of the two values previously specified. We then restart the v6.0.2 processes to pick up the new value.

To change the host name field for a process:

Tasks

1. In the administrative console, go to the configuration data for one of the processes on the new nodes:

   • For an application server, click...

             Servers > Server Types > WebSphere application servers > server. Then in the Additional Properties section, click > Ports > port_name .

   • For a node agent, click...

             System Administration > Node agents > node. Then in the Additional Properties section, click > Ports > port_name .

   • For a deployment agent, click...

             System Administration > Deployment manager. Then in the Additional Properties section, click > Ports > port_name .

2. Click View associated transports for the port associated with the DCS transport channel we want to review.

3. Click DCS_UNICAST_ADDRESS, and enter the name of the new host in the Host field.

4. Click OK> Save.

5. Repeat the previous steps until the new host name is added for all of the processes on the new nodes.

6. Select Synchronize changes with nodes, and then click Save again.

7. Stop all of the servers that contain the processes with configuration changes.

8. Restart these servers.

All of the processes can communicate with each other.

What to do next

If v6.0.2 processes are not configured properly, the v6.0 and v6.0.1 processes might not start or might not be able to connect to the v6.0.2 processes.

The condition can be detected in one of the following ways:

• v6.0 and v6.0.1 processes log the following message:

  HMGR0024W: An error was encountered while looking up the IP address for 
  the host name of a core group member. The host name is * and the server 
  name is myCell01\myCellManager01\dmgr. The member is excluded from the 
  core group.
  

  This message indicates that the host name for another process in the core group is an asterisk.

• The v6.0, v6.0.1, and v6.0.2 processes form separate views if the v6.0 and v6.0.1 processes do not connect to v6.0.2 processes. To detect these views, examine the HMGR0218 messages that the various processes logged. If the processes connect, the same message is logged across all processes. Specifically, processes connected have the same view identifier and the same number of processes in the view.

  HMGR0218I: A new core group view is installed. The core group is 
  defaultCoreGroup. The view identifier is (8:0.spoletoCell01\
  spoletoCellManager01\dmgr). The number of members in the new view is 2.