Interoperating with Version 6.0.2 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 Version 6.0.2 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 Version 6.0.1.2 processes exist, see Interoperating with Version 6.0.1.2 processes for additional considerations.

When processes are created on Version 6.0.2 or later nodes, the host name field in the DCS_UNICAST_ADDRESS endpoint is set to an asterisk. When you 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 Version 6.0.2 nodes interoperate with Version 6.0 and Version 6.0.1 nodes without Fix Pack 2 (6.0.1.2), because these earlier versions do not contain high availability manager multihome support. Version 6.0 and Version 6.0.1 processes do not recognize an asterisk as a valid value in the DCS_UNICAST_ADDRESS host name field. Therefore, these processes cannot connect to Version 6.0.2 processes configured with an asterisk in the DCS_UNICAST_ADDRESS host name field. When Version 6.0.2 processes must interoperate with Version 6.0 or Version 6.0.1 processes, the DCS_UNICAST_ADDRESS for all Version 6.0.2 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 Version 6.0.2 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 must then restart the Version 6.0.2 processes to pick up the new value.

To change the host name field for a process:

1. In the 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_name. 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 > dmgr. Then in the Additional Properties section, click > Ports > port_name .

2. Click View associated transports for the port that is associated with the DCS transport channel to review.

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

4. Click OK, and then click 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 containing the processes with configuration changes.

8. Restart these servers.

Results

All of the processes can communicate with each other.

What to do next

If Version 6.0.2 processes are not configured properly, the Version 6.0 and Version 6.0.1 processes might not start or might not be able to connect to the Version 6.0.2 processes.

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

• Version 6.0 and Version 6.0.1 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 Version 6.0, Version 6.0.1, and Version 6.0.2 processes form separate views if the Version 6.0 and Version 6.0.1 processes do not connect to Version 6.0.2 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 that are 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.