efficient parallel printing of the same document to N identical printers

[milahu]

cups is slowing down my printing process

when i send the same document to 10 identical printers
then cups runs the same filter pipeline 10 times

expected

cups should run the filter pipeline once
and send 10 copies of the result to my 10 identical printers

example

82 A4 pages
20 pages per minute duplex (Brother HL-L5100DN)
each printer takes 250 seconds

1 printer
high cpu load for 30 seconds

  0 send job: lp input.pdf -d my_printer
 28 printer starting
276 printer done

6 printers
high cpu load for 180 seconds

  0 send 6 jobs: lp input.pdf -d my_printer
 68 first printer starting
112 last printer starting
318 first printer done
362 last printer done

362 versus 276 seconds = 30% slower

considering the network traffic (100 Mbit/s)
sending the same document to 6 identical printers
should have an overhead between 1% and 5%

workaround

for now, i would be happy with a workaround
where i run the filter pipeline manually
and call lp final.xyz -d my_printer_$x

how would that work?

keywords

• mass production
• large volume printing of the same document
• job caching
• job sharing
• filter deduplication
• filter result caching
• filter result sharing
• run gstoraster only once
• run rasterizer only once
• print rasterized document
• raw printing
• direct printing

related

• At what point does CUPS actually call the rasterizer in the printing process?
• I have converted a pdf file to pwg/raster but how do I print it using pycups PrintFile function?
• CUPS bypassing interface

[dkosovic]

The Brother HL-L5100DN supports the following according to the link you posted:

• PDF 1.7
• PostScript 3
• PCL 6
• XPS

It also supports AirPrint according to the following page:

• https://download.brother.com/welcome/doc100479/cv_hll5100dn_eng_ap_a.pdf

As it supports AirPrint, it also effectively supports IPP Everywhere.

Add the printers as IPP Everywhere print queues, assuming you are using their Ethernet ports and they have IP addresses, e.g.:
sudo lpadmin -p queue1 -v ipp://xxx.xx.xxx.xx/ipp/print -m everywhere

As the printer has native PDF support, it'll be PDF in and PDF out for CUPS with close to zero CPU overhead for the QPDF based pdftopdf filter that comes with cups-filters.

You've posted this issue to Apple CUPS, but appear to be using OpenPrinting CUPS which has its own issues page:

• https://github.com/openprinting/cups/issues