HP 3000 Manuals HP 3000 Manuals
Lesson 1 Introducing Jobs
Introduction
Lesson 1 presents the following information about jobs and batch
processing:
* comparison of session to job processing
* descriptions of SHOWJOB display information
* effect of the job limit and jobfence on batch processing
Until now your logon time in this course has been in session mode. In
session mode, the computer acts on a single command at a time.
However, in job mode or batch processing, you use the STREAM command
to submit an entire series of commands
as a "batch" or "job" file to the computer.
STREAM MYJOB
MYJOB is a job file containing a "batch" of commands. The computer
processes these commands without additional input from you. Your results
generally are sent to a printer.
NOTE MYJOB and some other job files are ready for you to use with this
module. Your system manager put them there for your use.
Other job files on your system are incomplete. You will have a
chance to complete and run them as part of your study.
Advantages of job/batch processing
There are a number of advantages to job processing.
It's much more efficient than session processing. Jobs generally do not
require continuous input or your supervision. You can process a number
of job commands with a single command. While your job is processing,
your terminal is free for other work.
One other advantage of job processing is that the processing can be
scheduled to occur at a specific time. A job that requires a large
portion of the system's resources may be run at a time when the system is
not busy with interactive sessions or other jobs.
Comparison to sessions
How well can you distinguish between jobs and sessions? Label each item
below to show which refer to jobs and which refer to sessions.
--------------------------------------------------------------------------------------------
| |
| Q3-1 Which are characteristics of jobs? Of sessions? |
| |
| |
| a. interactive processing |
| |
| b. synonymous with batch processing |
| |
| c. does not require constant supervision |
| |
| d. submits a single command at a time |
| |
| e. can be scheduled to run at specified time |
| |
| f. most time/resource efficient |
| |
| g. executes with STREAM command |
| |
--------------------------------------------------------------------------------------------
More SHOWJOB information
You already know that the SHOWJOB command lists all jobs and sessions
currently on your system and provides you with the limits for each;
however, as you begin working with jobs, you will be interested in the
additional information displayed by SHOWJOB.
The following is an example of a SHOWJOB display:
___________________________________________________________________________
| |
| |
| JOBNUM STATE IPRI JIN JLIST INTRODUCED JOB NAME |
| |
| #S201 EXEC 20 20 MON 7:05A CONSOLE.SYS |
| #J30 WAIT D6 10S LP MON 6:30A JON.FINANCE |
| #S230 EXEC 55 55 MON 12:02P USER2.CLASS |
| #J35 INTRO 8 10S LP MON 5:45A STATS.PROJECT |
| #J32 EXEC 10S LP MON 4:30A MARY.PROD |
| |
| 4 JOBS: |
| |
| 1 INTRO |
| 1 WAIT |
| 3 EXEC; INCL 2 SESSIONS |
| 0 SUSP |
| JOBFENCE=6; JLIMIT=11; SLIMIT=20 |
| |
| CURRENT: 7/20/89 17:30 |
| |
| JOBNUM STATE IPRI JIN JLIST SCHEDULED-INTRO JOB NAME |
| |
| #J33 SCHED 9 10S LP 7/20/89 20:00 MARY.PROJA |
| #J34 SCHED 8 10S LP 7/20/89 22:00 USER2.CLASS |
| |
| 2 SCHEDULED JOB(S) |
| |
___________________________________________________________________________
The important terms in the display are described below:
JOBNUM Lists the number assigned by the system to sessions and
jobs. Numbers assigned are sequential. J indicates a job;
S indicates a session.
STATE Shows the session or job's processing state.
The five possibilities for jobs are:
INTRO The job is being submitted.
WAIT The job is waiting for system resources, or the job limit
may have been reached, or the job's priority is too low.
EXEC The job is executing.
SUSP The job was executing but is now suspended.
SCHED The job is scheduled to execute at a time specified by the
user.
NOTE Questions 2 through 12 refer to the SHOWJOB display.
--------------------------------------------------------------------------------------------
| |
| Q3-2 How many jobs in the preceding display are executing? |
| |
| |
| Q3-3 Which of the jobs in the display is being submitted? |
| |
| |
| Q3-4 Which job is awaiting execution? |
| |
| |
--------------------------------------------------------------------------------------------
JOBFENCE, JLIMIT, SLIMIT information
JOBFENCE Establishes the priority for jobs to execute. A job
must have a priority above the jobfence in order for the
job to execute.
JLIMIT Indicates the maximum number of jobs that can be executing
simultaneously.
SLIMIT Indicates the maximum number of sessions that can be logged
on at any one time.
The values for each of these are set by system management and may be
adjusted by them to meet the needs of system users.
IPRI (input priority)
This column displays a job's input priority only if that job is in the
WAIT or INTRO state, or has been scheduled to run at a later time. D6
means the job has an input priority of 6, but is deferred for later
execution. If a job is currently executing or suspended, the job's
priority value is not displayed. You might see QUIET in this column.
The QUIET means that the user has instructed the system not to interrupt
with messages from other users. (The console operator can still
interrupt a Quiet session with a WARN command message.)
Input priority values range from 1 (low priority) to 13 (high priority).
If you enter HIPRI in the !JOB command line, the priority will be set to
15, but only if you have SM or OP capability; otherwise, the job will be
submitted with the highest possible priority available at the time.
Jobs in the EXEC or SUSPEND state do not have IRPR values.
In order for a job to begin executing, the input priority value, IPRI,
must be greater than the current jobfence. Once the job has entered the
EXEC state, INPRI and the jobfence value have no further meaning for the
job.
--------------------------------------------------------------------------------------------
| |
| Q3-5 If the current jobfence is 7, which of the following jobs will execute? |
| |
| |
| a. JOBA which has an input priority of 7 |
| |
| b. JOBB which has an input priority of 8 |
| |
| c. JOBC which has an input priority of 6 |
| |
| Q3-6 If the current JLIMIT is 5 and five jobs are executing, what will be the |
| STATE of the next nonscheduled job submitted? |
| |
| |
--------------------------------------------------------------------------------------------
JIN and JLIST columns
These two columns show the device (LDEV) numbers assigned to input (JIN)
devices and output (JLIST) devices. Since sessions are generally input
and output from a terminal, these numbers are identical for sessions.
Because jobs are usually input from disk, and output is printed on the
line printer (LP), the JIN and JLIST designators for jobs are different.
INTRODUCED and JOBNAME columns
The INTRODUCED column shows the date and time the session or job was
started. For a job in the WAIT state, the date and time show when the
job was introduced with the STREAM command. As soon as the job enters
the EXEC state, the date and time show when the job entered the EXEC
state.
The JOBNAME column shows the user and account where the job originated,
preceded by the job name, if any.
If a job is scheduled for later submission, its state will be SCHED. It
will appear at the end of the SHOWJOB listing. Under the column
SCHEDULED-INTRO will be the date and time when the job is scheduled for
submission.
--------------------------------------------------------------------------------------------
| |
| Q3-7 At what time was Job 35 streamed? |
| |
| |
| Q3-8 From what account and by which user was Job 35 submitted? |
| |
| |
--------------------------------------------------------------------------------------------
Job and session summary
Just beneath the column information is a summary of information regarding
jobs and sessions currently executing or awaiting execution on the
system. The following information on the jobfence, job limit, and
session limit is a list of scheduled jobs with the times they are
scheduled to run.
--------------------------------------------------------------------------------------------
| |
| Q3-9 How many jobs and sessions can be run concurrently on this system? |
| |
| |
| Q3-10 According to the JLIMIT information provided, how many more jobs could be |
| executing at this time? |
| |
| |
| Q3-11 How many jobs have been suspended? |
| |
| |
| Q3-12 Which job will be the last to run on 7/20/89? |
| |
| |
--------------------------------------------------------------------------------------------
SHOWJOB parameters
Suppose that you want information about just one job.
SHOWJOB Jobnumber
Or perhaps you want to display only job processing information rather
than job and session information to your screen.
SHOWJOB JOB=@J
The SHOWJOB command has a number of parameters that allow you to specify
the kind of information to be displayed.
--------------------------------------------------------------------------------------------
| |
| Q3-13 Review the parameter information for SHOWJOB in the Help facility. Then |
| enter the SHOWJOB commands that do the following: |
| |
| |
| a. list job summary information |
| |
| b. list jobs that have been scheduled |
| |
| c. list information on all current jobs |
| |
| d. list information on job 105 |
| |
| e. list the status of all jobs that you might have submitted from your |
| account |
| |
--------------------------------------------------------------------------------------------
Lesson summary
1. The SHOWJOB command lists all jobs and sessions currently
executing or scheduled on your system.
2. In order for a job to execute, it must have an input priority
above the jobfence.
3. Jobs submitted after the job limit has been reached will be
assigned to a WAIT state until system resources are available for
processing.
4. Unlike sessions, jobs allow you to submit a series of commands for
processing, can be scheduled to run at specific times, and do not
require constant user supervision.
Exercise 3-1:lesson 1 review.
Indicate which of the following statements are true.
1. If the jobfence is 6, jobs must have an input priority of at least
7 in order to execute.
2. When the job limit is reached, the system will not allow you
stream any more jobs.
3. The job limit is the maximum number of jobs that can be executing
at any one time by the system.
4. Scheduled jobs must also have an input priority above the jobfence
in order to execute.
5. The job limit, session limit, and jobfence values may be set and
adjusted by any user.
********** End of Exercise 3-1 **********