[cups.general] Printer spool and missing print

[Johannes Meixner]

Hello,

On Mar 30 03:11 Giuseppe Ravasio wrote:
> On 03/30/2011 11:22 AM, Johannes Meixner wrote:
>> Therefore:
>> Either
>> you use a special backend which can query its recipient
>> if the further processing at the recipient has completed
>> (but then the backend would have to wait until the processing at
>> the recipient has fully completed which delays processing of a
>> subsequent print job until the current job has fully completed)
>
> As you know there is not a template of backend with such feature anywhere?

You wrote that you print to a Epson AcuLaser M4000N "via cups class".

I don't know if "via cups class" could make a difference here
compared to usual printing directly via a print queue.

You didn't tell but I guees that you access the AcuLaser M4000N
via its network interface.

In this case see
http://www.cups.org/documentation.php/doc-1.4/whatsnew.html
-----------------------------------------------------------------
What's New in CUPS 1.4
....
Networking
....
SNMP-based monitoring; the ipp, lpd, and socket backends
now report supply levels and printer status using SNMP queries.
-----------------------------------------------------------------

Furthermore see
http://www.cups.org/documentation.php/doc-1.4/network.html
--------------------------------------------------------------------
Network Protocols Supported by CUPS
....
AppSocket Protocol
....
The "waiteof" option controls whether the socket backend waits
for the printer to complete the printing of the job.
The default is to wait.
....
Internet Printing Protocol (IPP)
....
waitjob=false      Specifies that the IPP backend should not wait
                    for the job to complete.
waitprinter=false  Specifies that the IPP backend should not wait
                    for the printer to become idle before sending
                    the print job.
-------------------------------------------------------------------

Both together should mean that the socket and ipp backends
can wait until the actual printing has finished, provided
- you use CUPS 1.4 with the socket or ipp backend and
- the AcuLaser M4000N supports the generic CUPS SNMP queries and
- the results of the generic CUPS SNMP queries really indicate
   whether or not the actual printing had finished.

Regarding IPP, note
http://www.cups.org/documentation.php/doc-1.4/network.html
-------------------------------------------------------------------
.... since many printers do not implement IPP properly, only
use IPP when the vendor actually documents official support for it.
-------------------------------------------------------------------

But I do not have real experience with this.

Furthermore I assume it depends on the particular printer model
what it actually means when a particular printer device reports
via a SNMP query that it is "idle".

I think in the end the issue is the same as if you like to get
reliable accounting information from a device, have a look at
http://en.opensuse.org/SDB:Printer_Accounting

I think you need to try out if the socket or ipp backend actually
waits until the actual printing has finished on your particular
AcuLaser M4000N printer.

If not, it might be possible to somehow "misuse" a printer
accounting solution (e.g. PyKota) for your particular needs?

Again: I do not have real experience in this area.


Kind Regards
Johannes Meixner
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