Invoking a multi-versioned application
Two or more versions of the same application can be installed, enabled and available on a platform at the same time. You use the EXEC CICS INVOKE APPLICATION command if you want to invoke a specific or minimum version of a multi-version application.
Before you begin
- The name of the application.
- The name of the platform on which it is installed, or verify that it is installed on the current platform.
- The name of the operation that corresponds to one of the program entry points for the application to be invoked.
- The exact major version of the application you want to invoke.
- The exact or minimum minor version of the application you want to invoke.
About this task
Two or more versions of the same application can be installed,
enabled and available on a platform at the same time. However, only
one of those versions is visible to the EXEC CICS LINK command.
This version is the highest major and minor version of the application,
and its entry points are public. So an EXEC CICS LINK to
an entry point program always invokes the highest version of the application.
The entry points for lower levels of an application are private, and
so are not visible to EXEC CICS LINK.
Note: Micro
version is always hidden as it reflects an internal change; for example,
a bug fix. The caller always gets the latest micro version.
You
use the EXEC CICS INVOKE APPLICATION to invoke
an application via one of its program entry points, without having
to know the name of the entry point program and regardless of whether
its entry points are public. If no version is specified, then the
highest major and minor version (the public level) is invoked. This
is the same behavior as using an EXEC CICS LINK command
to the application entry point. However, a lower version that is enabled
and available can be invoked by using EXEC CICS INVOKE APPLICATION and
specifying an appropriate major and minor version. You can specify
that either an exact match on the application major version number
and minor version number is required, or that a minor version number
is the minimum that is required, but if a higher minor version is
available it is to be used. If multiple higher minor versions are
available the highest is used. The major version number cannot be
exceeded and must match exactly.For the full syntax of the EXEC CICS INVOKE APPLICATION command, see INVOKE APPLICATION.
Procedure
Results
When your program issues this command, CICS invokes the specified application at the appropriate entry point.