[Mailman-Users] load-balance 2.1.x

[David Lee]

(This is in relation to 2.0.9, but I would probably move to 2.1.11.)

I've been reading FAQ 4.75 ("How do I set up ... to load-balance ...") and
Barry's archived email of 2006/11/29 "Load-balancing mailman between two
servers".

They talk about setting up multiple "slices" for "qfiles".  But it's not
clear how this is done.  I suspect I need to copy the "QRUNNERS"
definition across from Defaults.py to mm_cfg.py, and then do some sort of
edit.  And that this edit should somehow specify both a power-of-2 number
of slices (same on both machines), and also some sort of specification of
which slices this machine should run (different on both machines).  But
what is that edit?  Is it changing the "1" for one or more of the QRUNNER
entries (which?) to something like "1:2" (machine1) and "2:2" (machine2)?

Have I missed something in the doucmentation about this particular aspect?


Looking more generally, is there any other overall advice on such
clustering?

I would plan:

o  two front-end Mailman machines, clustered via Linux-HA/heartbeat (of
which we already have experience).  Ideally these would run live/live,
maintaining a pair of round-robin service-IP addresses.  (With a machine
failure, the other machine would adopt the failed machine's service-IP.)

o  a central (NetApp) NFS server would store all the Mailman data (though
"mm_cfg.py" would presumably be maintained within each machine).  Are
there any other considerations about what data-storage would be best kept
per-machine?


So I'd need to set up that multiple slice/qrunner stuff.  And probably
(for unattended operation) arrange that failover would reconfigure the
good machine also to run all slices; similarly that failback (whether
manual or automatic) after recovery would revert to "only my slices"
operation.


Has this been written up anywhere?  If not, I'd be happy to keep notes of
the process and submit them back to the Mailman documentation if that
would help.

Thanks.


-- 

:  David Lee                                I.T. Service          :
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