Dear Ron,
At Coventry University we have developed a system which does this. It is
based on LPRng and IFHP but uses some code written in-house as a front
end to the users.
It has been in use since the start of this academic year and has worked
pretty well. The biggest problem has been performance. It works as follows:
There is a single queue (called VIRTUAL) which all jobs are submitted to.
Jobs can be submitted from NT work stations or Unix systems and I believe
there are even some Macs using it. The jobs remain in the virtual queue
until they are released by whoever submitted them. There are about 40 or
so printers in open access rooms around the campus which people can print to.
Each printer location has a workstation next to it (which is actually an
old PC running linux acting as an X term) In most cases there is one such
station to each printer but there are one or two places where such a station
controlls 2 printers. When someone wants to release the print jobs they have
submitted they go to any printer that is convenient and enter their username
and password on the application that is running on the X term. This was
written in-house in C++ using the QT library. They type in username/password
although they could also use a scanner to read ID card information if we had
enough scanners. They are then shown a list of the print jobs that are
in the virtual queue. They pick the ones they want and these are then sent
to the printer next to the station. Of course you will probably have realised
that all we are doing is an lpc move command to move from the virtual queue
to the one that is associated with that printer. Jobs that are not printed
are deleted from the queue after a while.
We do attempt to estimate the page count before each job is printed and get
the actual count using IFHP afterwards. This works well as we use HP 4/5
printers everywhere. The database that is used to store the users information
is MYSql which is also freely available. The application uses an in-house
authentication system which is fast and secure.
The students like the system apparently and it works well apart from one big
problem which is performance. It was running on a single Alpha 800 and the
single virtual queue ended up with many thousands of jobs in it. Today we
made a couple of changes. We moved it to a dual processor alpha 1200 and we
made 100 virtual queues instead of one. We still have the single queue for
people to submit to but all jobs are immediately routed to one of the 100
virtual queues using a simple hash code based on their username. We found
one that gives a pretty even distribution. We only installed this version
this afternoon but it seems to work a lot better.
The linux PCs that control the printers are self repairing so require no
maintenance. They can only run the PACS (as we call it) application and
nothing else so they are pretty secure.
We have plans for several enhancements to the system.
Anyway, if you would like to come to have a look, we would be happy to show
you what we have done. We are only about 30 miles away.
best wishes....
Colin Bruce
> On Thu, Mar 15, 2001 at 12:48:47PM +0000, [EMAIL PROTECTED] wrote:
>
> Hi is there anybody on the list in a university environment that is using lprng
> to provide charged printing to students ??
>
> Ron
>
> Ron McKeating
> Computing Services
> Loughborough University
> 01509 222329
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