-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

I have had a situation where several printers have been served by up
to 4 different spoolers (Apple IP share, LPRng, Windows TCP/IP and
some other unix lpd thing). And no, it does not always work very
well!

All my printers in this situation are HP with JetDirect cards, and
print jobs don't often get lost or corrupted, but the problem appears
to be with who the print chooses to listen to.  I have not
investigated far as I only control the LPRng spool so everyone else
can go away, but it appears that it's a first come first served basis
for which spooler connects to the printer first. The printer will
then service all jobs from that spooler, wait a bit, and the talk to
the spooler that manages to poll it next.  Tough luck if you have one
job in the LPRng queue, but there are a days and a half's worth of
printing in the Apple queue, and it gets in first!  The exception
appears to be the direct printing from the Windows spooler which
appears to takes priority over the other queues (we only let techs
print this way).


David Challenor <[EMAIL PROTECTED]>
Senior Computer Technician
Coventry School of Art and Design
Coventry University



- -----Original Message-----
From: [EMAIL PROTECTED] [mailto:owner-lprng@;lprng.com] On Behalf
Of Toby Blake
Sent: 01 November 2002 10:04
To: [EMAIL PROTECTED]
Subject: Re: LPRng: 2 print servers both spooling to one physical
printer


> It is a bad idea for the same reason a printer spooler was invented
> in  the first place: a printer cannot print two things at the same
> time  and iterleaving two printjobs isn't particular useful. This
> was for a  unix systems with many logged in users, each of which
> needs to print  something. Things doesn't change very much with
> network printers and  printing from multiple workstations; the
> printer can still only print  one thing at a time, and for that
> reason having only one spooler being  in charge of the printer will
> ensure everything runs smoothly. All  other systems will then
> submit their print jobs to that spooler 
> instead of directly to the printer.
>
> For a set of spooler systems to access one single printer there
> must  be a protocol to coordinate that access. In the LPD protocol
> there is  no such mechanism.

I should probably comment that I plan to operate like this for a very
short period of time, basically it's a way of getting one print
server to serve another print server's queues while it's being
upgraded, but because of the nature of our ldap propagation mechanism
(ldap is the source of the princap information) there's no way of
being entirely sure which of our clients will be looking at the
correct server at any one time - update propagation to clients takes
up to an hour, unless manually enforced.

I have run some simple experiments with two lprng print servers
serving the same printer and they seem to operate OK - if the printer
is busy, lprng on either machine waits until it's free, effectively
queueing jobs in both print servers.

Toby


- ----------------------------------------------------------------------
- -------
YOU MUST BE A LIST MEMBER IN ORDER TO POST TO THE LPRNG MAILING LIST
The address you post from MUST be your subscription address

If you need help, send email to [EMAIL PROTECTED] (or
lprng-requests or lprng-digest-requests) with the word 'help' in the
body.  For the impatient, to subscribe to a list with name LIST, 
send mail to [EMAIL PROTECTED]
with:                           | example:
subscribe LIST <mailaddr>       |  subscribe lprng-digest
[EMAIL PROTECTED]
unsubscribe LIST <mailaddr>     |  unsubscribe lprng [EMAIL PROTECTED]

If you have major problems,  send email to [EMAIL PROTECTED] with
the word LPRNGLIST in the SUBJECT line.
- ----------------------------------------------------------------------
- -------

-----BEGIN PGP SIGNATURE-----
Version: PGPfreeware 6.5.3 for non-commercial use <http://www.pgp.com>

iQA/AwUBPcKHqtppEniwd2F3EQKvbgCg38D9euoce+eX/PpnG5g27n8DEIwAoL0K
pv0gbzFwaWaMzbs7NaGg/jsr
=HebI
-----END PGP SIGNATURE-----


-----------------------------------------------------------------------------
YOU MUST BE A LIST MEMBER IN ORDER TO POST TO THE LPRNG MAILING LIST
The address you post from MUST be your subscription address

If you need help, send email to [EMAIL PROTECTED] (or lprng-requests
or lprng-digest-requests) with the word 'help' in the body.  For the impatient,
to subscribe to a list with name LIST,  send mail to [EMAIL PROTECTED]
with:                           | example:
subscribe LIST <mailaddr>       |  subscribe lprng-digest [EMAIL PROTECTED]
unsubscribe LIST <mailaddr>     |  unsubscribe lprng [EMAIL PROTECTED]

If you have major problems,  send email to [EMAIL PROTECTED] with the word
LPRNGLIST in the SUBJECT line.
-----------------------------------------------------------------------------

Reply via email to