Can we limit the number of active jobs on a given printer?

Kai Lanz lanz at stanford.edu
Wed Jun 16 11:14:02 PDT 2010


The other day I was surprised to see more than one active job being sent
to one of our plotters. The output of lpq for that plotter showed 7 jobs
with rank "active", and there were 7 backend processes running simultaneously.
Is that normal for CUPS? I had always thought there would only ever be one
active job on any given printer. It didn't cause a problem with printing, but
we have custom-written plotter control and accounting software that implicitly
assumes there can be at most one active job (one running backend). It would
help us if we could configure CUPS (or write a backend) so it would send jobs
to a printer strictly one at a time. Is there a way to do that?

MaxJobsPerPrinter doesn't do what we want; it limits the number of jobs that
can be spooled, not the number that can be active. And waitjob appears to be
an option for the IPP backend only.

This is RHEL 4 on Intel x86_64 with CUPS 1.1.22. The plotters are HP 800ps
and T1120ps DesignJets. The backend is a simple bash script that sends data
to the plotter through a pipeline of filters after confirming that the job to
be printed has been properly released by a valid user; it then marks the job
as "printed" in a log file.

--
Kai Lanz           Stanford University        School of Earth Sciences





More information about the cups mailing list