HP OpenVMS Systems Documentation

To see the characteristics defined on a system, enter SHOW QUEUE/CHARACTERISTICS.

Example

$ SHOW QUEUE/CHARACTERISTICS
Characteristic name                  Number
-------------------                  ------
EAST                                      1
WEST                                      2
NORTH                                     3
SOUTH                                     4

No characteristics are assigned to a queue by default. To assign characteristics to a queue, include the /CHARACTERISTICS qualifier with INITIALIZE/QUEUE, START/QUEUE, or SET QUEUE.

Example

$ SET QUEUE/CHARACTERISTICS=(EAST) LN03_1

To determine the characteristics defined for a queue, enter SHOW QUEUE/FULL.

Example

$ SHOW QUEUE/FULL LN03_1
Printer queue LN03_1, idle, on HERA::TTA3, mounted form DEFAULT
  <Printer queue on node HERA for an LN03 printer>
  /BASE_PRIORITY=4 /CHAR=(1) /DEFAULT=(FLAG=ONE,FORM=LN03$PORTRAIT
  (stock=DEFAULT)) /LIBRARY=LN03LIBRARY Lowercase
 /OWNER=[SYSTEM] /PROCESSOR=LATSYM /PROTECTION=(S:M,O:D,G:R,W:R)
 /SEPARATE=(RESET=(ANSI$RESET))

To cancel characteristics assigned to a queue, specify the /NOCHARACTERISTICS qualifier with INITIALIZE/QUEUE, START/QUEUE, or SET QUEUE.

14.6.3.6 Deleting Characteristics

To delete a characteristic definition, enter DELETE/CHARACTERISTIC. You must specify the characteristic-name with DELETE/CHARACTERISTIC.

If you know the number assigned to the characteristic but do not know the name, enter SHOW QUEUE/CHARACTERISTICS to display the names and numbers assigned to characteristics on the system.

If the system displays the following messages, a queue or job refers to the characteristic:

%DELETE-E-NOTDELETED, error deleting characteristic
-JBC-E-REFERENCED, existing references prevent deletion

You must remove all references to the characteristic before you can delete the characteristic. For information about removing references to a characteristic, see Section 14.8.5.

14.6.4 Specifying Batch Processing Options

You can use queue options to control batch job performance and the use of system resources by processes executing batch jobs.

Use the following qualifiers with INITIALIZE/QUEUE, START/QUEUE, or SET QUEUE to set these queue options:

Although the following qualifiers are not specific to batch queues, they are commonly used to control batch job performance and the use of system resources by batch processes:

For more information about these limits, quotas, and priorities, refer to the following manuals:

• The INITIALIZE/QUEUE command in the OpenVMS DCL Dictionary
• The OpenVMS Performance Management

By default, a process running a batch job uses values taken from the UAF record of the user submitting the job or from system parameter settings. If you specify values for any of these options, processes for jobs executed in the queue will use the values you set unless the user specifies values when the job is submitted. (A user can specify values for CPU time and for the working set options default, quota, and extent.)

A user-specified value cannot exceed the value you set for the queue. If you did not specify a value, the user-specified value cannot exceed the value specified in the associated UAF limit or system parameter.

The following sections provide guidelines for choosing values for these options:

Choose a value based on how quickly you will allow batch jobs to progress. If you choose a value equal to the system parameter value DEFPRI (typically 4), jobs in this queue will progress at the same rate as typical interactive jobs. This choice might be appropriate for systems that have an abundance of available CPU time.

If you choose a value less than DEFPRI, jobs in this queue will potentially progress more slowly than the typical interactive job. CPU time will be allocated to jobs in this queue only after servicing jobs of DEFPRI priority.

If a queue is defined for a very special purpose---for example, high-priority jobs---a value greater than DEFPRI (for example, 5) might be appropriate. However, this choice can have a significant negative effect on the performance of other users and batch jobs.

14.6.4.2 Job Limit

Keep this value low when using a base process priority of DEFPRI or greater, because each batch job can affect the performance of interactive jobs.

14.6.4.3 Working Set Default, Quota, and Extent

If you do not specify values for these options, a job uses the value specified in its owner's user authorization file (UAF) record.

In general, the working set quota and extent values specified in the UAF record for each user are sufficient. However, you can specify more generous or stringent values for a queue, depending on the purpose of the queue. For example, you can encourage users to submit large jobs (such as compiling and linking large programs) as batch jobs to reserve interactive use of the system for jobs that do not require extensive resources, as follows:

• Set a large working set size for batch jobs by specifying larger WSQUOTA and WSEXTENT values when you create the batch queue.
• Restrict the working set size of interactive jobs by providing smaller WSQUOTA and WSEXTENT values in users' UAF records.

You can restrict and expand the amount of time a job is allowed in the CPU by setting CPU limit values.

Do not set CPU time limit values too low. When a job's CPU time limit is exceeded, the job is terminated with an error status. If working set values (explained in Section 14.6.4.3) are set too low, the system might use memory less efficiently but the jobs can still complete normally. However, if CPU time limit values are set too low, the system might terminate jobs that are making legitimate and authorized use of the CPU.

For example, you might use a CPU time limit on a batch queue devoted to execution of newly coded software that could unexpectedly enter a CPU loop. The CPU time limit would terminate infinitely looping jobs so they do not waste the CPU resource. However, you must be careful to choose a sufficiently high time limit so normally executing jobs do not terminate prematurely.

Another way to control allocation of the CPU resource is to create a special-purpose batch queue that shifts execution of its jobs to a less busy time of day when CPU time is more available.

14.6.4.5 Swapping

Typically, swapping is enabled on batch queues. However, for a special-purpose, high-priority queue, you might disable swapping. This provides a favorable status to jobs in this queue by removing them from consideration when memory must be reclaimed from processes (through the operating system's swapping and trimming mechanism).

For more information, refer to the OpenVMS Performance Management.

14.6.4.6 Options for Memory-Constrained Systems

On memory-constrained systems, total the pages required for the batch working sets on all batch queues. Also make sure that enough fluid memory remains for interactive jobs.

Fluid memory can be reassigned from one process to another through swapping and paging. (You can calculate fluid memory as the space that remains when you subtract the number of pages permanently allocated to the operating system from the total memory. To obtain these values, enter SHOW MEMORY.)

14.6.4.7 Optimizing Batch Queues for the Sort/Merge Utility

You can improve the efficiency of the OpenVMS Sort/Merge utility (SORT/MERGE) by designating one batch queue for sorting jobs and giving this queue a very large working set quota.

You can also set process quotas for greatest SORT efficiency. The values recommended here are based solely on SORT considerations; you should integrate other system considerations with these to determine appropriate values.

• Working set extent per process (WSEXTENT system parameter)
  For maximum sorting efficiency, use the /WSEXTENT qualifier with INITIALIZE/QUEUE, START/QUEUE, or SET QUEUE to set this value on the queue to the largest value any sorting job would ever need. Generally, the smaller the working set, the slower the sort.
  If you want to sort large files in batch mode, you need to set the WSEXTENT system parameter to a large value to accommodate the sort.
• Virtual page count per process (VIRTUALPAGECNT system parameter)
  For maximum sorting efficiency, set this system parameter to at least 1000 pages (on VAX systems) or pagelets (on Alpha systems) more than the maximum working set extent. Although SORT limits the size of the sort data structure to the process's working set extent, if work files are required, SORT can use the extra memory for I/O buffers. If this parameter is too low relative to the working set extent, SORT might be unable to create buffers for the work files when the files cannot be sorted in memory.

The queue manager uses the following criteria to determine the scheduling order for batch and print jobs that are eligible for processing:

1. Job scheduling priority
   The queue manager checks the job's scheduling priority. The job with the highest scheduling priority value is processed first. The job scheduling priority is different than the base process priority or current process priority. The user can specify job scheduling priority with the /PRIORITY qualifier of the PRINT or SUBMIT command.
2. Size (optional, and applies only to output jobs)
   By default, the job size of an output job is checked. Among jobs of identical scheduling priority, the smallest job is processed first.
   The job size is not checked if the queue has been created, started, or modified to use the /SCHEDULE=NOSIZE option.
3. Submission time
   If the jobs' scheduling priorities are identical, the job that was submitted first is processed first.

How to Perform This Task

To specify job scheduling options, follow these steps:

1. Decide if you want the order of print jobs to be based on size.
2. Decide if you want to set a block limit on jobs to be printed.

Commands for Job Scheduling Options

Use the following commands to specify job scheduling options:

The sections explain how to set job printing priorities and sizes.

How to Prioritize Jobs by Size

To prioritize jobs based on their sizes, use the /SCHEDULE=SIZE qualifier with INITIALIZE/QUEUE, START/QUEUE, or SET QUEUE. (The /SCHEDULE=NOSIZE qualifier prints jobs in the order they were submitted, regardless of size.)

In the following example, /SCHEDULE=SIZE (the default), causes short jobs to print before longer ones on the print queue LPA0_PRINT:

$ INITIALIZE/QUEUE/SCHEDULE=SIZE LPA0_PRINT

If you enter this command while pending jobs are in any queue, its effect on future jobs is unpredictable.

How to Limit the Size of Jobs

To limit the size of print jobs, use the /BLOCK_LIMIT qualifier with INITIALIZE/QUEUE, START/QUEUE, or SET QUEUE. By default, printer and terminal queues are created with no block limit, so jobs of any size will be printed. You can specify only an upper limit or both upper and lower limits.

In the following example, LPB0_PRINT has a block size limit of 50, indicating that this queue is reserved for jobs smaller than 51 blocks.

$ INITIALIZE/QUEUE/BLOCK_LIMIT=50 LPB0_PRINT

You might also want to limit the size of jobs during certain hours of the day. You can submit a batch job that runs a command procedure to set a maximum block limit of 500 blocks for a queue at 8:00 a.m. The command procedure might resubmit itself and remove the block limit after 5:00 p.m. each day. This lets users print jobs of any size after normal work hours, when the printing work load is lighter. Users can specify the /AFTER qualifier with the PRINT command to specify that a job is to be printed after a specific time.

14.6.5.2 Changing the Scheduling Priority of a Job

If a batch or print job cannot be processed, it is placed in a pending state and is not processed until the cause of the pending state is resolved. For more information, see Section 14.8.2.

To change the scheduling priority of a job, use the /PRIORITY qualifier with SET ENTRY in the following format:

The following example changes the scheduling priority of a job to 50:

$ SET ENTRY/PRIORITY=50 1131

Do not confuse the job scheduling priority with the base process priority on a queue. The job scheduling priority value must be in a range of 0 through 255, where 0 is the lowest priority and 255 is the highest. The default value for /PRIORITY, which refers to the job scheduling priority, is the value of the system parameter DEFQUEPRI (usually set at 100).

14.6.6 Using Banner Pages

Banner pages are specially formatted pages that you can set up for queues, to help identify and separate output jobs when they exit a printer. Banner pages also help identify and separate files within jobs.

Two types of banner pages are:

• Job pages are banner pages that identify and separate jobs.
• File pages are banner pages that identify and separate files within a job.

Most sites use only a subset of the available banner pages at any given time. The following table describes the types of banner pages you can use:

Table 14-2 describes the information found on job flag pages, file flag pages, job trailer pages, and file trailer pages.