Juzshura Additionally, be aware of how this information uses references to printers: Study these before restarting JES2 for the purpose of initialization parameter specification modification. The modification heading is listed for all parameters on all statements; it is specified as follows, with the minimal intervention level:. This information documents all JES2 initialization statements, in alphabetic order. If you are restarting JES2 for the purpose of changing initialization statements or parameter values, a cold start is only required for a limited number of JES2 parameters. Purpose of this information This information referencs JES2 initialization statements and their parameters and provides summary charts that highlight details of the statements.

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Sham So, short holds of, say, 0 to 10 can cause various JES2 Performance and Availability Considerations 5 processes to take too long to complete too much checkpoint thrashing. Over allocating this value will give a slight performance overhead as the job queue elements JQE control block increases by four yuide for each additional 32 spool volumes.

You can use the following tools for analysis of performance-related data. Table 2 provides a list of the JES2 resources and the corresponding initialization statements that you can adjust. Processes within JES2 which do not need to access the checkpoint will run uninterrupted even during a time frame when the checkpoint is in a non-useful state.

So, you can run them with confidence. All combinations of checkpoint data sets on DASD and coupling facility structures are supported as potential error recovery scenarios through the checkpoint reconfiguration dialog.

Spool partitioning Spool partitioning or fencing allows track group allocation across explicit volumes. IBM may have patents or pending patent applications covering subject matter described in this document. There is a sample reduction program supplied in SYS1. JES2 allocates spool space for a job by dividing each spool volume into track groups. The following are the most commonly used traces that are used for JES2 performance analysis: Whether an RMF report shows the checkpoint as performing well is often immaterial to actual delays that are caused by waiting for access to the checkpoint.

Releases the hardware reserve. In duplex inotialization the 4 KB pages are changed. IBM may use or distribute any of the information you supply in any way it believes appropriate without incurring any obligation to you.

The more members added to the MAS, the bigger the benefit of the coupling facility structure. Besides simply queueing the input and output, the spooling subsystem schedules it.

A useful command to help diagnose this is the following: The system paused its other processing and waited while the next card was read, or while the next line was printed. However, in some cases, if the checkpoint is held long enough, the process can be done in one checkpoint cycle. Use the online Contact us review redbook form found at: Because spool volumes are read by a number of vendor products including SDSFany change to how spool addressing operates affects these products.

JES2 restarts it automatically within a few minutes. The order of decrease is to stop initiators serving lower importance service classes first. See HASP origin storyif interested. You should adopt dual or duplex mode.

Consult your local IBM representative for information on the products and services currently available in your area. However, these are only starting points. The JES2 health monitor is intended to address situations where JES2 is not responding to commands and where it is not possible to initializayion the issue.

This value reflects the number of checkpoint accesses in that interval. Start high, and then lower it if there are problems and you do not see the messages when initializattion wanted to.

The imagery of spooling was probably taken from processes that wind some material such as thread, string, fabric or gift wrapping paper onto a spindle or spool. Preliminary to that, we might want to know a little about the basic pieces involved. Related Posts


Abstract for JES2 Initialization and Tuning Guide

All jobs in the member are lost. If the member to be warm started is in a multi-access spool configuration with any other active members, only this member is warm started. JES2 will continue processing jobs from where they were stopped. Default: LIST specifies that JES2 is to print all the statements in the initialization data set and any error flags that occur during initialization. This option when used in conjunction with job queue validation is useful for several special situations that require immediate track group map validation.







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