1 Need for Scheduler
CA-7 is an online, real time, interactive system, which automatically controls, schedules and initiates work according to time driven and/or event driven basis. It is used to reduce manual work load.
1.1 What is a JOB?
A task or unit of work directed to CPU in batch environment.
A set of JCL control statements with one JOB statement and one or more steps that are executed on a computer.
1.2 Batch Processing
Execution of a set of interrelated JOBs based on either dates or times or events or dependencies.
Batch processing removes the need for manual intervention.
1.3 Features of CA-7
Ø CA-7 scheduler provides intelligent workload management for OS/390 environment.
Ø Ensures throughput is maximized.
Ø Ensures OS/390 resources are efficiently used.
1.4 CA-7 Pre-requisites
Ø JOBS need to be defined to CA-7.
Ø Scheduling criteria needs to be defined for each job.
Ø JCLs that are defined to CA-7 must reside in a CA-7 Library or a PDS that can be dynamically accessed by CA-7.
Ø Base Calendar must be set.
1.5 CA-7 Common Terminology
1.5.1Scheduling
Each job can have unique scheduling criteria that can be based on either Dates and time or triggering.
1.5.2Requirements
Predecessors that must be defined before a job can run.
They are called Predecessors as they must precede the job
They can be completion of another job, manual task and creation of dataset.
They can be defined in addition to its scheduling criteria.
1.5.3Schedule ID
Ø They are the numbers from 1 to 255, which are used to identify scheduling variations.
Ø It allows scheduling of the same job in different ways.
1.5.3.1 Type of jobs:
1. Demand
2. Auto
3. Sscn (scheduled scan jobs)
4. Run
1.5.4Example for SCHEDULE ID
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1.5.5Schedule Scan
The schedule scan program scans the CA-7 database, selects the jobs that are scheduled for processing in the next few hours, and bring them into the request queue.
1.5.6QUEUE
The disk datasets that hold the records of CPU jobs during different phases of processing.
There are eight such disk datasets :
Ø Request Queue
Ø Trailer Queue
Ø Ready queue
Ø Active Queue
Ø Hold Queue
Ø Prior-run Queue
Ø Preprocessing queue
Ø Post processing queues
1.5.7CA-7 Execution of Jobs
The following steps explain the execution order of the jobs submitted to CA-7:
1. The Job starts in REQUEST queue.
2. As the job is put in the request queue, at the same time, the JCL copy is written to the TRAILER Queue.
3. The job record is moved to READY Queue, only when all the requirements are satisfied.
4. JCL is submitted to JES when the resources are available.
5. When the Job goes active on the system, the JOB record is moved to the ACTIVE queue.
6. At JOB termination, CA-7 returns the job record to REQUEST Queue.
7. If the termination is unsuccessful, then the record is held for operator intervention in the ‘HOLD’ queue.
8. Here the JCL remains in the TRAILER Queue so that it can be restarted.
9. If job is successful, the record is moved to PRIOR-RUN queue and JCL is deleted from TRAILER Queue
10. Remaining two Queues hold the data for non-computer tasks.
Entire job flow:
Late job analysis:
1.5.8Online Mode:
Step 1 : Enter CA7 at the command prompt.
Step 2 : Enter option 1 for database enquiry
Step 3 : Enter Job Name for which you wish to obtain Scheduler information
Step 4: Note the Job information is retrieved as shown below. We can enter appropriate
option number at the prompt to get the relevant data.
option number at the prompt to get the relevant data.
Step 5 : Option 1 will provide trigger Information
Step 6 : Option 2 will provide triggered Job Information
Step 7 : Option 3 is for Job requirements
Step 8 : Option 4 is for DSN requirements
Step 9 : Option 7 is for determining the Dependant Job.
Step 10 : Option 6 is for determining the BASE CALENDAR.
COMMAND: 6
SCROLL : CSR
************************************* Top of data ************************
**********************************************************
**
** CA-7 SCHEDULE CALENDAR FOR JOB=JOB2
** DATE 01333
** BASE CALENDAR SCAL01CD (DEFAULT) SCH
**
***********************************************************
***********************************************************
**
** MONTH 01 JAN
**
** SUN MON TUE WED THU FRI SAT
**
** 02 03 04 05
** 07 09 10 11 12
** 14 16 17 18 19
** 21 23 24 25 26
** 28 30 31
***********************************************************
***********************************************************
1.6 CA-7 DATABASE ENQUIRY:
A FORCAST IS A DISPLAY OF WHAT JOB(S) OR SYSTEM(S) WILL RUN DURING A SPECIFIED TIME PERIOD. IF YOU USE JOB SEQUENCE, THE JOBS ARE LISTED IN JOBNAME ORDER. IF YOU USE EXECUTION SEQUENCE, THE JOBS ARE LISTED IN THE ORDER OF EXECUTION.
THERE ARE TWO TYPES OF FORCASTS AVAILABLE WITH THIS FACILITY:
FORCAST - SUMMARY REPORT. MANY JOBS PER PAGE
LISTING START DATE/TIME, END DATE/TIME,
TRIGGERING.
FORCAST WITH DETAILS – FULL DETAIL REPORT. ONE PAGE PER JOB
LISTING START DATE/TIME, END DATE/TIME,
TRIGGERING, JOBDEPS, REQUIREMENTS, ETC. )
COMMAND ===> ENTER THE NUMBER WHICH CORRESPONDS TO THE TOPIC YOU WISH TO DISPLAY OR (UP) TO PRIOR PANEL
Note: Press F1 for help from any screen for further details
