Here's my original question:
Some of our users use a canned application to submit batch jobs to the system.
In the background the application is using the "at" command to submit the job
along with its scheduled time. At times there is a need to submit several
batch jobs to run over night in a certain sequence but we have found that DUNIX
does not process batch jobs in a consistent manner if there are several jobs
waiting to run from the same single-threaded queue. For example, we have
submitted 3 jobs to run in succession, one at 04:00, one at 04:15 and one at
04:30 and lets say we had another batch job which was submitted earlier to the
same single-threaded queue at 03:45 and is currently active and doesn't complete
until 05:30. When 05:30 rolls around and the active job completes, there is no
guarantee as to which order the 3 pending jobs will be processed in since
their scheduled time has passed. Initially, I thought the system should take
them in on a "first-in first-out" basis but this is not the case, the observed
behaviour is inconsistent. So I am wondering if there is any reliable way to
schedule batch jobs so they will be processed in an orderly sequence?
Summary::
Basically, in summary, when it comes to the functionality of "at" or "cron" on
Unix what you see is what you get... very simple and unsophisticated batch
handling. A few respondents suggested that if you need to have jobs run in a
certain order just put the steps in to a script in the required order of
execution or separate the commands with semi colons.
Others suggested getting 3rd party batch management software such as:
GQNS -
http://www.gnqs.org/home.htm
QMASTER -
http://www.qmaster.com
Sector7 -
http://www.sector7.com
There was another suggest to allow the application to submit jobs to the queue
not using "at" but some other means and then " have a process you write look
at the queue periodically and always run things in the order implied by the
scheduled time of initiation, so that things will be single threaded through
the queue, and run in the implied order."
Thanks to all those who replied.
Received on Sat May 15 1999 - 12:42:06 NZST