list server got slower ?

Sam Sharpe lists.redhat at samsharpe.net
Mon Dec 28 19:46:45 UTC 2009


2009/12/28 Mail Lists <lists at sapience.com>:
>  However, if things go slow enough there is a potential problem that the
> lists may overwhelm the outgoing MX servers.
>
>  The observation I had is simply that the delay (which is in the
> outgoing MX) has increased from 1-2 mins to 10 possibly higher. It is
> the change in the delay that I thought was of interest.

That's the point I was trying to make. Higher latency does not
necessarily mean throughput goes down, it may in fact go up - That's
fundamental to a lot of engineering disciplines.

Lets take the example of mail-servers sending out similar messages, to
keep this on-topic. We have two possible delivery methods (there are
more obviously):

A)  We can either send out each message in the order it is queued, one
message at a time.
B)  We can hold each message a while and wait to see if the same
message comes in for a different recipient on the same mailserver  -
and then send them both in the same SMTP transaction.

Strategy (A) has the lowest latency. Strategy (B) has a higher
latency, as it will take a "while" to fill the buffer and pop out the
same message. Ultimately with millions of messages in the pipeline,
Strategy (B) will have a higher throughput, because it is more
efficient to queue multiple mails together.

So my point being, an increase in Latency is not something to be
concerned about.

What intrigues me is that people seem to have some kind of expectation
of "immediate" email delivery. Last I looked, email wasn't defined as
a reliable transmission method with any kind of time guarantee.

--
Sam




More information about the fedora-list mailing list