Core group members interact with each other through a variety of protocols such as the discovery protocol, the failure detection protocol, and the view synchrony protocol. Each of these protocols define a set of formatted messages that core group members exchange according to a common algorithm.
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 version as long as all members of a particular core group are configured to use the same version.
New protocol versions are added to the product if new messages, or new algorithms are required to support new product features, or to improve core group performance. Because the new messages, or new algorithm might not be compatible with the existing messages or algorithm, a new protocol might not be able to interoperate with the old version of the protocol.
DCSV0005I: DCS Stack DefaultCoreGroup at Member DIAMONDCell01\DIAMONDCellManager01\dmgr: Started. Stack version information: DCSBV_WAS6_1_20060409. Stack protocol information: 61002.
The Stack protocol information value at the end of this message indicates the protocol version that is being used. For example, a value of 51001 means the 6.0.0 version is being used. A value of 61002 means the 6.1.0 version is being used.
HMGR0226I: The core stack configuration parameter IBM_CS_HAM_PROTOCOL_VERSION has been set to 6.0.2.31.
This message indicates that the high availability manager protocol version 6.0.2.31 is being used.
The protocol version settings for each of these two categories are independent of each other.
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, you must make sure that all of the core group members are running at a WebSphere Application Server code level (VRM) that is equal to or greater than the new protocol version.
When you have determined that you can use a newer core group protocol level with a particular core group, use either the IBM_CS_WIRE_FORMAT_VERSION or the IBM_CS_HAM_PROTOCOL_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.
Core group bridges provide the mechanism that is used to represent and manage the cross core group state that is used by WebSphere Application Server components. Part of the management process for this cross-core group state is to perform core group bridge state rebuilds whenever there is a change in the number of running core group bridges in a topology. The core group bridge state rebuild is the means by which core group bridges calculate the ownership, and distribution of the cross-core group state among the running set of bridges.
[7/9/08 17:12:20:749 EDT] 00000030 UserCallbacks E HMGR0142E: An error occurred in a component called back by the High Availability Manager The exception is java.lang.ArrayIndexOutOfBoundsException at com.ibm.ws.cluster.propagation.bulletinboard.BBDescriptionManager.getOrderedBytes(BBDescriptionManager.java:618)
The following tables summarize for each protocol category the minimum level of the product that core group members must be running at before they can be associated with a specific protocol version. These tables also describe the new capabilities that were added in each protocol version.
Use these tables to determine which protocol versions you can use with a particular core group, and then use either the IBM_CS_WIRE_FORMAT_VERSION or the IBM_CS_HAM_PROTOCOL_VERSION core group custom property to configure all of the members of that core group to run using the newest of those protocol versions that is supported by the level of the product on which you are running. The high availability manager automatically detects the configuration changes and starts to use the new core group protocol version with these core group members.
Version ID | Required Minimum product Level | Description |
---|---|---|
6.0.0 | Any | This protocol version is the original or base version. All versions of the high availability manager can use this protocol. If you do not specify a particular wire format protocol version, the high availability manager uses this version. |
6.0.2.9 | 6.0.2.9 for Version 6.0.2, and 6.1.0 for Version 6.1. | This protocol version was included in the 6.0.2.9 service pack, and in Version 6.1 of the product 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 | 6.1.0 for Version 6.1 | This protocol version was included in Versions 6.1.0 of the product. This version adds core group scalability improvements, and more support for large topologies. |
Version ID | Required Minimum product Level | Description |
---|---|---|
6.0.2.31 | 6.0.2.31 for Version 6.0.2, 6.1.0.19 for Version 6.1 | This protocol version is the original or base version of the high availability manager protocol, and is available in the 6.0.2.31, and higher, and 6.1.0.19, and higher versions of the product to facilitate core group bridge scalability. This protocol version is recommended for topologies that contain multiple core groups and core group bridges as part of their configuration. |