You 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 Version 7.0 or later and WebSphere Application
Server Version 6.1 Feature Pack for Web Services.
WS-Transaction policy type enablement
For
a Version 6.1 Feature Pack for Web Services server,
you can enable the WS-Transaction policy type by including it in a
policy set, but you cannot configure it. For a Version 7.0 or later server, you 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
Version 6.1 Feature Pack for Web Services and
Version 7.0 or later servers, the following
behavior occurs:
- If a Version 6.1 Feature Pack for Web Services server reads a WS-Transaction
policy type file that is generated by a Version 7.0 or later server, the server
enables the WS-Transaction policy type, but ignores any configuration
information in the file.
- If a Version 7.0 or later server
reads a WS-Transaction policy type that is generated by a Version 6.1 Feature Pack for Web Services server, the server enables the
WS-Transaction policy type by using a value of Supports for the WS-AtomicTransaction
and WS-BusinessActivity protocols. This value is equivalent to the
existing behavior of a Version 6.1 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 WebSphere Application Server, wherever WS-Transaction
1.1 is supported, WS-Transaction 1.2 is also.
A WebSphere Application
Server Version 6.x server supports WS-Transaction 1.0. A Version 7.0 or later server supports WS-Transaction
1.0, 1.1 and 1.2.
No special restrictions apply
to a cell with both
Version 6.x and
Version 7.0 or later servers, except for
a mixed-version cluster that requires failover for high availability.
In a mixed-version cluster, a
Version 7.0 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 Version 7.0 or later servers
that are configured to fail over and that are configured to use WS-Transaction
1.1 or 1.2, you cannot add an earlier version server to the cluster.
- For a mixed-version cluster, where the servers are configured
to fail over, any Version 7.0 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 that are configured to fail over, any Version 7.0 or later server in the cluster
that is configured to use WS-Transaction 1.1 or 1.2 cannot start if
there are also servers at an earlier version.