For z/OS platforms

Planning to use optimized local adapters on Liberty for z/OS

Plan how to implement WebSphere optimized local adapters (WOLA) in your Liberty server environment.

Before you begin

For CICS® Transaction Server for z/OS® to communicate with optimized local adapters, the minimum required version of CICS Transaction Server for z/OS is version 4.1.

About this task

If you have applications that are written in native languages, such as Cobol, PL/I, C/C++, and high-level assembly languages, that run under z/OS batch, Customer Information Control System (CICS), or UNIX System Services environments, you can use optimized local adapters to directly call between the native-language application and Java-based business logic on a Liberty server. You can use optimized local adapters to make the following calls:
  • Inbound calls from an external address space to Enterprise JavaBeans (EJB) applications that are deployed on a local Liberty server
  • Outbound calls from an application that is running under the Liberty server on z/OS to a server program that is running in an external address space
If you have a large number of native-language applications that you want to use on Liberty, implementing optimized local adapters provides the following benefits:
  • Performance improvement
  • Identity context propagation
  • Local binding support
  • Gateway or proxy for legacy assets on z/OS systems

Procedure

  1. Review the existing business and middleware applications in your environment to determine which application processes would benefit from using optimized local adapters.
    Choose processes that you can remove and replace with calls to the optimized local adapter native API callable services.

    For more information about when to use optimized local adapters, see Optimized local adapters on Liberty for z/OS and Optimized local adapters usage scenarios for Liberty for z/OS.

  2. If you plan to propagate a System Authorization Facility (SAF) user ID from Liberty for z/OS to the enterprise information system (EIS), verify that the Liberty server is using a SAF-based user registry.
    For more information, see Activating and configuring the SAF registry on z/OS.
  3. Review the optimized local adapters samples.
    There are several examples that are included when you install Liberty for z/OS. For information about using the samples, see Optimized local adapters samples for Liberty.
  4. Decide how to use optimized local adapters.
    You can use the optimized local adapters to make inbound or outbound calls.
    1. Use the optimized local adapters to call inbound to Liberty server EJB applications.

      The following image shows the flow of an inbound CICS call to a Liberty server EJB application.

      Figure 1. Using CICS
      CICS inbound call to a Liberty server EJB application
    2. Use the optimized local adapters to call programs in external address spaces from Liberty server applications.

      The following figure shows the flow of an outbound Liberty server call to a CICS transaction.

      Liberty server outbound call to a CICS transaction

    For more information about using optimized local adapters, see Enabling the Liberty server environment to use optimized local adapters and Optimized local adapters APIs on Liberty for z/OS.