On Tue, Jan 29, 2002 at 02:40:56PM -0500, Barry A. Warsaw wrote:
MM> Barry: With the new qrunner infrastructure, does qrunner still MM> need to lock the lists during delivery? If qrunner doesn't MM> modify config.db anymore, could it open config.db read only?Remember that now, we have usually 7 queues, and each one has its own
Yep.
runner process. One of the advantages of this is that we can really isolate lock acquisition to a finer granularity. In fact, OutgoingRunner -- which processes qfiles/out files, and thus is the process that actually calls SMTPDirect -- does not lock the lists for the normal delivery processing. It simply shovels messages from the queue to smtpd and doesn't need to update any list information, as that's all done before the message gets to the outgoing queue.
Awesome, just what I was hoping for.
There's one exception (of course ;). If your smtpd ever returns synchronous errors, then Mailman has to lock the list in order to register bounces. However, Mailman only does this periodically, and this is controllable by the variable DEAL_WITH_PERMFAILURES_EVERY in Mailman/Queue/OutgoingRunner.py (it's not a mm_cfg.py variable).
That's not a real problem. Even if there is a race condition somewhere, this case should be sufficiently rare for the race not to happen.
By default this is set to 1, but you could crank it up so that the culling of the known bounces is done less frequently. OTOH, if your
Good to know.
MTA is set up to never do recipient tests/deliveries synchonously (and you're not delivering to local users), you should never have such delivery failures to deal with, thus you'd never need to lock the list.
Thanks a bunch. This should definitely allow for load sharing and some failover capability (the second server periodically rsyncs the NFS exported mailman tree in case the first list server, which exports ~mailman minus qfiles which is a symlink to local disk, dies. So, if this happens, you can move a symlink and continue with one server and an rsynced copy of the whole tree that is hopefully not too old)
Marc
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