Printing multiple copies on remote printers

Anonymous anonymous at easysw.com
Thu Apr 21 06:08:32 PDT 2005


I am seeing similiar issues with local queues.  It appears that the jobs get queued multiple time.  It is generating multiple job ids for only 1 requests.  I end up getting anywhere from 2 to 10 copies of the same request.  I am seeing this both on Solaris 9 with cups 1.1.19 and the RHEL 3.0 version 1.1.17-13.3.22.

Is anyone else seeing this?
Is it a problem with cupsd or lp or both?
What information do you want to help debug this?

> russell-cups at stuart.id.au wrote:
> > This bug has been observed in cups-1.1.20final+rc1 that
> > comes with Debian, and cups-1.1.22 compiled from source.
> >
> > Remote printers are occassionally printing multiple
> > copies of jobs.  None of the jobs had the "copies"
> > option set.
> >
> > The multiple copies was caused by two things:
> >
> > 1.  Made http_wait() did not handle EINTR.
>
> This is an issue, but your fix is not the correct implementation
> since it only handles a single interruption.
>
> > 2.  The wait in ipp_http_read was too short for connections
> >     that run over the internet.
>
> Setting a 2 minute wait here is not appropriate; http_wait() is
> only used when reading fragments in non-blocking mode, and only
> the scheduler uses this mode.  Putting a 2-minute wait in the
> scheduler opens CUPS up to additional DoS attacks but will not
> resolve the problems you are seeing.
>
> > Note:
> >     While both these bugs need to be fixed, neither completely
> >     solves the original multiple copies problem.  To solve
> >     that no data should be printed if there was a read or
> >     other error.
>
> The usual response to HTTP or IPP errors in the initial query
> phase of the backend's job submission is to retry the request or
> connection.
>
> As we have never seen this particular problem before, I would
> appreciate tcpdump/ethereal packet dumps of the traffic between
> client and server so that we can determine at what point the
> transaction is failing.
>
> Thanks!
>
> PS - you can post this problem and the dump files using the STR
> form at:
>
>      http://www.cups.org/str.php
>
> --
> ______________________________________________________________________
> Michael Sweet, Easy Software Products           mike at easysw dot com
> Internet `Printing and Publishing Software       http://www.easysw.com





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