Re: [exim-dev] Randomising retry times?

Michael Haardt wrote:
> Philip Hazel wrote:
>> That sounds extreme and complicated, difficult to explain, and
>> liable to errors, for what is a situation case.

I'd agree with that. Obfuscating retry times any further wouldn't help
much, I guess, ...

> My problem is not with mail from outside, but inside the cluster.

... but hat's a good point. I see this problem on our cluster very
clearly. We're using a 2-stage system, with "smart" relay hosts and
mailbox servers. If one mailbox server gets overloaded, (or offline)
refusing SMTP connections, Mail gets queued on the relay hosts. When the
mailbox server is available again, the (8) relay hosts start delivering
mail more ore less at the same time, hitting the mailbox server quite hard.

I'm not sure whether randomized retry times would solve the problem,
though. Some form of ratelimiting (as implemented in exim allready) may
be the better (more deterministic) solution, but may also influence
regular mail traffic. In any case this needs some hands-on experience
with the concerned system.


JM2C,
daniel