[6512] in Release_7.7_team
Printing configuration change
daemon@ATHENA.MIT.EDU (Evan Broder)
Mon Nov 16 15:16:37 2009
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Date: Mon, 16 Nov 2009 15:16:29 -0500
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From: Evan Broder <broder@MIT.EDU>
To: release-team@mit.edu
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Apparently explicit mail about this never went here.
As of today, I deployed a change to cluster machines only that causes
them to completely bypass the local CUPS daemon. All CUPS client
actions on cluster machines will now go directly to printers.mit.edu,
the CUPS server that mmanley has been working on.
This means that all print queues served by printers.mit.edu (which is
to say, all print queues) will show up in the picklist on cluster
printers. It also means that printing may appear slower because GUIs
will hang until jobs have been completely transmitted to
printers.mit.edu. On the other hand, jobs now have to pass through
fewer servers, and in particular, no longer pass through a server run
by SIPB^Wme. It also means that it's not possible to configure new
queues for your private non-Athena printer on cluster machines, but
the decision was made that this was not a problem.
This specific mechanism doesn't let us switch to printers.mit.edu for
non-cluster machines, because it's not possible to configure local
print queues. Nor can we simply use a local CUPS daemon and its
BrowsePoll feature, as we're currently using for cups.mit.edu, against
printers.mit.edu, because retrieving the list of queues from
printers.mit.edu is prohibitively slow.
To make this transition for non-cluster machines work, we need two
things. First, we switch from BrowsePolling against cups.mit.edu to
cluster-printers.mit.edu, which only serves printers of type DORM or
CLUSTER. We also need to provide an add-athena-printer script, which
will configure an arbitrary queue in Moira on the local workstation
only.
In summary,
* clusters use printers.mit.edu (this is done)
* non-clusters use cluster-printers.mit.edu and add-athena-printer
(this is not done)
- Evan
