[cups.development] [RFE] STR #2681: check of snmp status of printer before sending job

[Johannes Feigl]

> On Jan 22 03:40 Johannes Feigl wrote (shortened):
> > if i send an e.g. 10 printjobs to the mashine all of the are store in
> the
> > mashine and they are finished for cups.
> >
> > if i now have a problem with the printer, i don't know (from the
> cups)
> > which has not been printed yet and i cannot move the jobs to an other
> > printer.
> >
> > so it would be usefull, if cups would make a SNMP-check on the
> printer, of
> > the printer is ready to print (no paper jam, or other jobs to
> perferm)
> > before cups is sending the job to the printer.
> 
> I do not understand how this should help against loss of jobs.
> 
> Assume there is such a check, the printer may be filled up
> with printjobs nevertheless because the printer could be
> ready to print all the time while the jobs are sent.
> But then while it actually prints e.g. the third job,
> the printer firmware may crash or there is a memory corruption
> in the printer (or a built-in harddisk in the printer dies)
> so that all data in the printer would be lost.
> 
> On the other hand if the backend would wait for each job
> until its last page was actually printed before a subsequent
> job is sent to the printer, the printer's throughput would
> decrease in particular under high load. In the end such a
> "wait-until-actually-printed" could reduce a high performance
> printer to something like a small-office/home-office device.
> 
> To be really safe against loss of jobs inside printers
> I think it is best to use PreserveJobFiles, see
> http://www.cups.org/documentation.php/ref-cupsd-conf.html
> 
> To avoid misunderstandings:
> I don't mean that something like "waitprinter" for a backend
> is useless. I only like to point out that there are drawbacks
> (not 100% safe against loss of data and/or reduced performance).

hi

Let me tell you more about the issue:
In my case I'm using a fax server solution. All incoming fax are
getting received by a server and the server is printing these jobs.

The reason is, because they're mostly orders from customer, and it's
easier the handle the order when you got it on a sheet of paper
and not via email. (there are also drawings etc. on the orders)

Somebody who is writing the orders into our ERM-system just
take all of this printed pages. When after that the printer gets a
problem, I even don't know which was the last page, that's my biggest
problem, not the document itself, they are all saved on the server.

I know that this would slowdown the print jobs/printers, but in our case
there are only 200-300 print jobs on a day (most of them have a lot of
pages).

Do you now better understand the problem?

Regards,
Johannes