Abstract for JES2 Initialization and Tuning Guide · How to send your comments to IBM · Summary How to initialize JES2 in a multi-access SPOOL configuration. JES2 Initialization and Tuning Guide. z/OS JES2 Initialization and Tuning Guide contains the following information in support of JES2 Email Delivery Services. JES2 initialization statement and parameter summary tables · JES2 initialization statement descriptions · APPL(jxxxxxxx) – Application Characteristics.

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The output of this command is provided as is. Some small development company might have just one job class for everything. It discusses the key components of the JES2 infrastructure in the context of performance goals. We do not recommend placing both checkpoints on coupling annd structures or placing the primary checkpoint on DASD and the secondary checkpoint on a coupling facility structure. You should adopt dual or duplex mode.

Such jobs can receive space from more volumes than if the job spends its life on a single system. Identifying issues with JES2 performance degradation One of the reasons this study was done is because JES2 provides no internal performance monitor. After you have identified the rogue member, you might want to identify tujing which process PCE it is spending the most time by using the following command: Together they form a multi-access spool configuration MAS.

Initilaization using any of the other traces, you must analyze the raw formatted data to determine what is occurring.

WLM attempts to distribute the initiators across all members in the sysplex to balance the use of the systems while taking care that jobs with affinities to specific systems are not hurt by WLM guife. Start high, and then lower it if there are problems and you do not see the messages when you wanted to. The checkpoint cycle time then refers to the total time it takes for each processor in the complex to obtain ownership of the checkpoint, hold it, and gkide release control.


IBM z/OS JES2 Initialization and Tuning Reference (SA)

So that methodology was pretty well doomed. Bottlenecks, it might be said.

Only low-usage data sets if any should ttuning allocated on the same volume as the checkpoint data set. Queues of jobs awaiting conversion, output, or purge are growing. Because only two bytes are allocated for the track portion of the address, no spool data set can cross the 64 KB track boundary on a volume. Just because one member is unable to access the queues another member might be performing useful work.

Winter Spring Checkpoint Dates. This initializattion discusses JES2 processor utilization, checkpoint and spool considerations, workload manager WLM managed initiators, scalability, command processing, and identifying issues with performance degradation.

Sample JES2 initialization data set

Example 4 shows the output for one of these systems. Checkpoint-related useful work should not be confused with JES2 work.

Remote job entry lines time out. When you review the allocation of checkpoint data, your interests are not solely performance related. When initializatiln this command to display information pertaining to a large range of jobs, started tasks or TSO users. The intermediate write activity updates the in-storage queues with new changes from the system and brings the DASD copy up to date.

Sample JES2 initialization data set

Spool affinity is not controlled by a JES2 initialization statement. It wrote printed output to a line printer, one line at a time. Trademarks The following terms are trademarks of the International Business Knitialization Corporation in the United States, other countries, or both: In dual mode, the change log is used, and the 4 KB pages are written only if the change log is filled. If all members are significantly greater than what was set, then your goal might not be attainable.


The spool also refers the direct access device that contains the spool data sets. JES2 Performance and Availability Considerations 13 General scalability tracking As your environment grows, you should understand how this growth affects the limitations of key operating system components.

The holding area is called spool space. It also provides a gulde to have spool space online and ready to guive if spool volumes start to fill up. Example 1 shows sample output from this command. JES2 acquires, uses, and frees the checkpoint on a time slice basis which is set by the installation.

Abstract for JES2 Initialization and Tuning Reference

JES2 attempts to maximize the performance of spooling operations, which ultimately benefits the throughput of work through the JES2 installation. This is particularly useful where a PSO application is in use and experiencing problems. After the queues have been updated to assign an output element to a printer, the printer no longer needs the checkpoint and can obtain the data from the spool even though the checkpoint is owned by another member of the complex.

In general, this process takes two checkpoint cycles to complete. This data should be compared for all systems to establish which member has the most activity. New initiators are started in circumstances such as the following: Purpose of this information This information describes JES2 initialization statements and their parameters and provides summary charts that highlight details of the statements.