Core group protocol versions
Core group members communicate with and monitor each other through a variety of protocols such as the discovery protocol, the failure detection protocol, and the view synchrony protocol. This collection of individual protocols for a particular core group is often referred to as the core group protocol. Each core group protocol is assigned a version identifier, that use to select the version of a core group protocol that is appropriate for your environment.
A core group protocol consists of a set of formatted messages that the core group members exchange according to a common algorithm. A new version of a core group protocol is provided whenever high availability enhancements require format changes that make the new message set incompatible with the previous version of the message set. The high availability manager can use any supported core group protocol versions as long as all members of a particular core group are configured to use the same version.
When to select a new core group protocol version
Core group protocol versions are always cumulative. Any functional enhancement that is provided in a previous protocol, is included in any subsequent protocols. It is recommended that you always use the latest protocol version whenever possible. But, before configuring the members of a core group to use a new protocol version, make sure that all of the core group members are running at a WAS code level (VRM) that is equal to or greater than the new protocol version. For example:
- A core group containing a mix of v6.2.7 and 184.108.40.206 core group members must be configured for the 6.0.0 core group protocol version because the v6.2.7 core group members can not use the v6.2.9 core group protocol.
- A core group containing a mix of v6.2.9, 220.127.116.11 and 6.1 core group members can be configured for either the 6.0.0 protocol or the 18.104.22.168 protocol, but not the 6.1.0 protocol because the v6.2.9, and 22.214.171.124 core group members can not use the V6.1.0 core group protocol.
- A core group containing only 6.1.0 members can be configured for either the v6.0, 126.96.36.199 or 6.1.0 core group protocol.
When you have determined that use a newer core group protocol level with a particular core group, use the IBM_CS_WIRE_FORMAT_VERSION core group custom property to configure all of the core group members to run with that newer version. You can change the value of this property while the core group members continue to run. After you save and synchronize the changed value to all of the nodes containing core group processes, the high availability manager automatically detects the configuration change and starts using the new core group protocol version to communicate with the core group members.
Supported core group protocol version IDs
A core group protocol version ID indicates the first the version, release, and modification level in which that version is included. The following table lists the supported core group protocol version ID.
VID Description 6.0.0 This is the original or base version. All versions of the high availability manager can use this protocol. If you do not specify a particular protocol version the high availability manager uses this version. 188.8.131.52 This version was included in the v6.2.9 service pack to facilitate core group bridge scalability. This version is recommended for large topologies that contain multiple core groups and core group bridges as part of their configuration. 6.1.0 This version was included in V6.1 to add core group scalability improvements, and more support for large topologies.
The support for previous protocol versions complies with the WAS n/n-2 interoperability standard.
Core group Discovery Protocol Core group Failure Detection Protocol Core group View Synchrony Protocol Core groups (high availability domains) Related tasks
Select the version of a core group protocol
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