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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All combinations of checkpoint data sets on DASD and coupling facility structures are supported as potential error recovery scenarios through the checkpoint reconfiguration dialog. You can use the following tools for analysis of performance-related data.
Abstract for JES2 Initialization and Tuning Reference
If the HOLD tubing is set lower than the time it takes for the primary write to 2 JES2 Performance and Availability Considerations complete, the hold time is extended until the primary write completes. To do so, you can use the following command: On the other hand, a hold that is too long means that a member is holding the checkpoint and not doing anything, thus wasting a shared resource.
IBM may use or distribute any of the information you supply in any way it believes appropriate without incurring any obligation to you. This paper discusses JES2 processor utilization, checkpoint and spool considerations, workload manager WLM managed initiators, scalability, command processing, and identifying issues with performance degradation. Other reasons could be error recovery dump processing or some other type of failure. There is spool sharing. In cases such as printers pausing, slow commands, or slow initiation of work, it is often lack of access to the checkpoint that is causing the delay.
There are input classesalso called job classes, that control scheduling and resource limits. Some small development company might have just one job class for everything. This information could include technical inaccuracies or typographical errors. Checkpoint-related useful time When discussing the JES2 checkpoint cycle, it is important to understand the concept of checkpoint-related useful time. You may copy, modify, and distribute these sample programs in any form without payment to IBM for the purposes of developing, using, marketing, or distributing application programs conforming to IBM’s application programming interfaces.
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This information documents all JES2 initialization statements, in alphabetic order. The checkpoint data set regardless of whether it resides on a coupling facility structure or a DASD volume contains a backup copy of the JOB and OUTPUT queues, which contain information about what work is yet to be processed and how far along that work has progressed. The number of active JES2 processes and frequency of the following: Checkpoint-related useful work should not be confused with JES2 work.
There is a lock table in the coupling facility structure associated with a serialized list. Questions on the capabilities of non-IBM products should be addressed to the suppliers of those products.
This adjustment has instant effect and reflects real-time values as opposed to an average over a stated period. In general, this process takes two checkpoint cycles to complete. Many JES2 processes do not require checkpoint or require it very infrequently.
After you have identified the rogue member, you might want to identify in which process PCE it is spending the most time initiallization using the following command: Retailing and E-tailing Chapter 15 Checkpoint Solutions. For example, performance can be seriously degraded if you allow your checkpoint data set to share the same volume as that of your spool. For best initializzation, dedicate spool volumes that is, do not share a volume with paging data sets or initializaton data sets.
Big companies typically create complicated sets of job classes, each class defined with its own limits for resources such as execution time, region size, even the time of day when the jobs in each class are allowed to run. It is a controlled environment where each member is allowed limited and regulated data set access.
IBM z/OS JES2 Initialization and Tuning Guide (SA)
This enhancement improves the performance of the sysplex with better use of the processing capacity of each system. You can then analyze the trace information that is in the dump. It also discusses performance tools that are available for analyzing performance-related data. Think of the checkpoint as in two states: We do not recommend placing both checkpoints on coupling facility structures or placing the primary checkpoint on DASD and the secondary checkpoint on a coupling facility structure.
JES2 restarts it automatically within a few minutes. The final write is the same as an intermediate write, but after the final write starts, no further changes to the in-storage queues are allowed. An external writer is a program that reads and processes sysout files, and such a program can route the output to any available destination.
In reality, the HOLD parameter is a minimum hold value. There is a sample reduction program gkide in SYS1. Spooling means a holding area tuningg disk is used for input jobs waiting to run and output waiting to print. Placing the primary checkpoint on DASD while the secondary checkpoint resides on a coupling facility provides no benefit to an installation.