Parallel Sysplex implementation considerations
When using Job Optimizer Pipes in a Parallel Sysplex environment, the following considerations apply:
- Job Optimizer Pipes uses the Coupling Facility (CF) to share data (for example, the Pipe List and data blocks of Global pipes). Because the Coupling Facility is used by other IBM MVS components (for example, JES2, IBM VTAM®, and DB2), using Global pipes can affect the performance of those components. Coupling Facility response time has a major impact on the performance of Global pipes.
- Because all systems in a Parallel Sysplex environment are treated as one system by Job Optimizer Pipes, all Job Optimizer Pipes address spaces in a Parallel Sysplex environment must have identical configurations. Each Job Optimizer Pipes address space should use exactly the same set of rules, the same Pipe Policy List, the same installation parameters, and so on. The Job Optimizer Pipes address spaces must be initialized with modules that have the same level (and share the same load library, if possible). Operator commands (for example, Rule Load, Reload PGM, Set Mode) that can affect Job Optimizer Pipes configuration or operation mode are distributed by the Job Optimizer Pipes address space that is receiving the command to all other Job Optimizer Pipes address spaces in the Parallel Sysplex environment.
In a JES3 complex, there is one Global processor and up to 31 Local processors. When a job is submitted to JES3, the first process it goes through is called Converter/Interpreter (C/I). As part of the C/I process, JES3 analyzes JCL statements and converts them to internal control blocks. This process can occur within the JES3 address space or in a dedicated address space called FSS, and it can be performed in any system in the complex. After the job passes the C/I process, it can be executed on any system in the complex. (For example, a job that is submitted on system A can go through the C/I process on system B and be executed on system C.)
The dynamic pipe setting is performed in two phases. The first phase is part of the C/I process (using JES3 exit IATUX04), and the second phase occurs when the job starts executing in a dedicated initiator. To allow consistent operation, each phase requires that the same set of rules will be active.
Because the two phases can occur on different systems, Job Optimizer Pipes must be activated on each system on which jobs that are using pipes will be converted or run, and the same set of rules should be loaded by all Job Optimizer Pipes address spaces.
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