On Tue, 29 Oct 2013, Osborne, Paul (paul.osborne@???) wrote:
> Hi,
>
> We have hit a slightly odd condition over the weekend where one of av/spam
> hosts had a load of mail in its queue which it was happily trundling
> through whilst still accepting email, in our case it would have been handy
> if it had stopped accepting email until the queue size had reduced to a
> predetermined amount until it had started accepting email again. This
> would have ensured a reasonable load across similarly specced systems and
> reasonable spread of mail shipping speed.
>
> Now I know I could use something like:
>
> smtp_load_reserve 5
>
> In order to stop accepting email until the system load was reduced however
> this was not the issue, nor was disk space so checking for disk space or
> inodes was not an option either.
Whether you throttle based on queue length or system load, to solve
this problem you need do it *relative to your other servers*.
If *all* your servers had had long queues that they were successfully
trundling through, throttling on the queue length would have slowed
things down even more. Having this one server stop accepting mail
whilst the queue drains only helps because the others are free.
--
Dr. Andrew C. Aitchison Computer Officer, DPMMS, Cambridge
A.C.Aitchison@??? http://www.dpmms.cam.ac.uk/~werdna
