WS-Transaction and mixed-version cells
We must consider WS-Transaction policy type enablement and behavior, and the WS-Transaction specification level to use, when a cell contains servers at different versions; for example, WebSphere Application Server v7.0 or later and WAS v6.1 Feature Pack for Web Services.
WS-Transaction policy type enablement
For a v6.1 Feature Pack for Web Services server, we can enable the WS-Transaction policy type by including it in a policy set, but we cannot configure it. For a v7.0 or later server, we can both enable and configure the WS-Transaction policy type. Configuration information is written to the WS-Transaction policy type file.
In a cell with both v6.1 Feature Pack for Web Services and v7.0 or later servers, the following behavior occurs:
- If a v6.1 Feature Pack for Web Services server reads a WS-Transaction policy type file generated by a v7.0 or later server, the server enables the WS-Transaction policy type, but ignores any configuration information in the file.
- If a v7.0 or later server reads a WS-Transaction policy type generated by a v6.1 Feature Pack for Web Services server, the server enables the WS-Transaction policy type using a value of Supports for the WS-AtomicTransaction and WS-BusinessActivity protocols. This value is equivalent to the existing behavior of a v6.1 Feature Pack for Web Services server.
WS-Transaction specification level
WebSphere Application Server supports the WS-Transaction 1.0, WS-Transaction 1.1 and WS-Transaction 1.2 specifications. In practice, version 1.2 of the WS-Transaction standard is functionally equivalent to version 1.1, so within WAS, wherever WS-Transaction 1.1 is supported, WS-Transaction 1.2 is also.
A WAS v6.x server supports WS-Transaction 1.0. A v7.0 or later server supports WS-Transaction 1.0, 1.1 and 1.2.
No special restrictions apply to a cell with both v6.x and v7.0 or later servers, except for a mixed-version cluster that requires failover for high availability. In a mixed-version cluster, a v7.0 or later server might fail over to an earlier version server that does not support WS-Transaction 1.1, and that therefore cannot recover WS-Transaction 1.1 protocol messages. In this situation, there are the following implications:
- For a cluster of v7.0 or later servers configured to fail over and configured to use WS-Transaction 1.1 or 1.2, we cannot add an earlier version server to the cluster.
- For a mixed-version cluster, where the servers are configured to fail over, any v7.0 or later server configured to use WS-Transaction 1.1 or 1.2 cannot fail over to a server in the cluster configured to use WS-Transaction 1.0.
- For a cluster of servers configured to fail over, any v7.0 or later server in the cluster configured to use WS-Transaction 1.1 or 1.2 cannot start if there are also servers at an earlier version.
Related:
Use WS-Transaction policy to coordinate transactions or business activities for web services Configuration for high availability WS-Transaction policy settings Transaction service settings