The PRIOR task scheduler uses three criteria for controlling main memory and CPU utilization by the tasks. These criteria are
the task category
the multiprogramming level
the task priority
Detailed information on these criteria can be found in the manuals “Introduction to System Administration” [6] and “Performance Handbook” [5]. In the following, only information that is relevant for the SM2 reports is discussed.
Task category
In BS2000, 16 task categories are distinguished at present, i.e. the 4 standard categories
SYS (system tasks)
TP (inquiry-and-transaction tasks)
DIALOG (interactive tasks)
BATCH (batch tasks)
and up to 12 categories that can be defined freely by the system administrator.
Multiprogramming level
The multiprogramming level denotes the number of tasks of a given category that may use main memory concurrently, i.e. the number of active tasks of a category.
In the MODIFY-TASK-CATEGORIES command the system administrator uses the category attributes
MIN MPL
MAX MPL
WEIGHT
to specify the relative priority of each category in order to make decisions regarding activation (= allocation of authorization to use main memory).
MIN MPL is used to specify a minimum number of active tasks of a category. The system tries to reach the specified MIN MPL value first.
MAX MPL is used when there is no fixed limit, i.e. activation continues even after the maximum MPL value as long as no resource bottleneck occurs.
WEIGHT is used to control the sequence of activation.
Report output
The REPORT CATQ statement is used to request the output of the CATEGORY QUEUE report.
HOST0001 SM2 CATEGORY QUEUE CYCLE: 60 S SAMPLES: 144 <date> <time> |CATEGORY | TASKS IN SCHEDULER QUEUES | MPL | | NAME |CPU-Q|IO-Q |PAG-Q| ACT | WACT | NADM | ALL | MIN | MAX |WEIGHT| +---------+-----+-----+-----+------+------+------+-------+------+-----+------+ | SUM | 1.8| 0.2| 0.0| 148.6| 0.0| 0.0| 499.1| | | | | SYS | 0.6| 0.0| 0.0| 64.0| 0.0| 0.0| 168.9| 30| 64| 512| | DIALOG | 0.0| 0.0| 0.0| 0.0| 0.0| 0.0| 11.0| 1| 3| 126| | BATCH | 0.4| 0.1| 0.0| 16.2| 0.0| 0.0| 36.0| 16| 17| 6| | TP | 0.2| 0.0| 0.0| 44.0| 0.0| 0.0| 58.0| 45| 47| 52| | TP1 | 0.0| 0.0| 0.0| 0.0| 0.0| 0.0| 0.0| 0| 2| 126| | BATCHDB | 0.0| 0.0| 0.0| 0.0| 0.0| 0.0| 0.0| 0| 2| 126| | BATCHF | 0.3| 0.0| 0.0| 22.0| 0.0| 0.0| 69.2| 22| 24| 2| | DIALOG1 | 0.1| 0.0| 0.0| 0.6| 0.0| 0.0| 154.2| 1| 2| 96| | DIALOG2 | 0.2| 0.1| 0.0| 1.8| 0.0| 0.0| 1.8| 2| 3| 70|
Monitoring information
This report contains the totals (SUM) for all categories in the first line following the table header. The data for the individual categories (up to 16) is output in the following lines.
The columns contain the following data:
CATEGORY NAME | Name of task category |
TASK IN SCHEDULER QUEUES | |
CPU-Q | Average number of tasks of a category waiting to use the processor(s) and of tasks currently using the processor(s) (task queues 0 and 1, excluding the SM2 monitoring task) |
IO-Q | Average number of tasks of a category waiting for IO termination (tasks in task queue 4 with IO pend code) |
PAG-Q | Average number of tasks of a category waiting for paging (tasks in task queue 3) |
ACT | Average number of active tasks of a category |
WACT | Average number of inactive ready tasks of a category (tasks in task queue 5) |
NADM | Average number of tasks of a category waiting for activation (tasks in task queue 6; this value is supplied only if PCS is used) |
ALL | Total number of all tasks of a category |
MPL | |
MIN | Average value of the minimum multiprogramming level used to determine the activation of tasks of a category |
MAX | Average value of the maximum multiprogramming level used to determine the activation of tasks of a category. This value is used primarily to prevent overloading by setting a load limit. |
WEIGHT | Average weight used to determine the activation sequence for the task categories |
In PCS mode the MIN, MAX and WEIGHT values are modified dynamically, i.e. they no longer contain the system administrator specifications. | |