(c) 2015 UCL, Dr. Andrew C.R. Martin
simq is a very simple program batch queueing system written to meet the needs of a web site that has long running high-memory programs that may be invoked by the user and therefore only one can run at a time without slowing the machine to a halt.
It simply places jobs in a queue by placing the command in a file that
lives in the queuedir directory. The queue manager then pulls jobs
off one at a time (in the order they were submitted) and runs them.
Usage: simq [-v[v...]] [-p polltime] -run queuedir
simq [-v[v...]] [-w maxwait] queuedir program [parameters ...]
simq -l queuedir
-v Verbose mode (-vv, -vvv more info)
-p Specify the wait in seconds between polling for jobs [10]
-w Specify maximum wait time when trying to submit a job [60]
A lock file is created when submitting a job - this specifies
the maxmimum number of seconds the code should wait for
this to clear.
-l List number of waiting jobs
-run Run in daemon mode to wait for jobs
Note that queuedir must be a full path name.
The queue manager is invoked by running simq in the backgrounded with
the -run flag. e.g.
nohup nice -10 simq -run /var/tmp/queue1 &
This must be done as root.
The queue directory (queuedir) will be created if it does not exist,
with appropriate permissions to allow anybody to write to the
directory and with the sticky bit set to stop other people deleting jobs.
Note there is no restriction on who may submit jobs to the queue.
To submit a job, run simq as, for example:
simq /var/tmp/queue1 myprogram param1 param2
Jobs may not be submitted as root.
To obtain the number of waiting jobs, do:
simq -l /var/tmp/queue1
Installation could not be simpler. Simply type
make
to compile the program - it requires no libraries or dependencies -
and place the simq executable somewhere in your path
(e.g. /usr/local/bin or $(HOME)/bin). There is only one executable
which acts as both the queue manager and the submission tool.