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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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You can send license inquiries, in writing, to: Affinities are used when resources are plentiful. 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. IBM may use or distribute any of the information you supply in any way it believes appropriate without incurring any obligation to you. The number of active JES2 processes and frequency of the following: Preliminary gukde that, we might want to know a little about the basic pieces involved.

Whether an RMF report shows the checkpoint as performing well is tuinng immaterial to actual delays that are caused by waiting for access to the checkpoint.

Chapter Security considerations – JES3 to JES2 Migration Considerations [Book]

Rather than always writing to spool, it simply writes to storage buffers and takes a dump when the JES2 performance issue is encountered.

It is often difficult to determine if there is a JES2 performance issue. The checkpoint mechanism is as follows: Free time The free time is initializatiob amount of time when no member is using or obtaining the checkpoint.


This can be combined with trace ID 20 to get a picture of the general overhead of guode selection overhead. You can change the value dynamically using an operator command or the online SDSF interface. Use the online Contact us review redbook initializattion found at: Remote job entry lines time out. Some forms of contention-driven access can provide benefits.

The affinity is system based, not job based.

However, there can be increases in JES2 processor consumption. These tunong should be re-evaluated if the JES2 workload is not distributed homogeneously across all the members of the MAS.

It wrote printed output to a line printer, one line at a time. This isolation can prove beneficial for systems with a tendency to be output intensive, so protecting the other members of the MAS. To ensure spool space is initializatioon wasted, performance is not degraded, and sufficient spool space is catered for, take care with the following parameters of SPOOLDEF: Consequently, this should be performed at a quiet time.

IBM z/OS MVS mainframe overview of JES2

The most obvious example of this situation is a printer. Spool partitioning Spool partitioning or fencing allows track group allocation across explicit volumes. Purpose of this information This information describes JES2 initialization statements and their parameters and provides summary charts that highlight details of the statements. Any references in this information to non-IBM Web sites are provided for convenience only and do not in any manner serve as an endorsement of those Web sites.

This information references the following publications for further details about specific topics. This maximizes DASD use as well as central and virtual storage usage.


This information should be used as capacity planning data to gauge whether you have significant growth and need to take any action. However, these are only starting points. The checkpoint cycle is primarily made up of the following components: For best performance, dedicate spool volumes that is, do not share a volume with paging data sets or other data sets.

z/OS JES2 Initialization and Tuning Guide

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The LOCKOUT parameter reflects the time between a member being denied access to the shared queues and the time the controlling member is assumed to be down. 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. If all members are significantly greater than what was set, then your goal might not be attainable.

The main benefit of fencing is availability. Abbreviated forms of these titles are used throughout this document.

In effect, spooling is a near-synonym for queueing. A useful command to help diagnose this is the following: The intermediate write activity updates the in-storage queues with new changes from the system and brings the DASD copy up to date.