Measuring spare capacity

[Martin Hepworth]

Hi

what hardware and what OS/MTA???

what performance tuning have you done

what does load average look like?

might want to reduce batch set and max children to see how it gets
on..theses params are very much trial and error...

--
Martin Hepworth
Snr Systems Administrator
Solid State Logic
Tel: +44 (0)1865 842300


MailScanner wrote:
> I am trying to get a handle on the amount of spare capacity in my MS
> boxes.
>
> We are running two MS which handle about 250,000 messages by day (MRTG
> count by recipient). The 'Max Unscanned Messages Per Scan' and Max
> Unsafe Messages Per Scan' are both set at 50 and max children at 15.
>
> I isolated a day's worth of maillog entries out of a rotated file and
> looked at some stats. Counting all instances of 'Found X messages
> waiting' I found that 75% had just one message, 17% two, 5% three and
> the more populous batches hardly registering at all. Doing the same for
> 'Scanning X messages' I found a slightly wider spread but tapering off
> quickly after 15.
>
> These are the distributions for the first 15 counts:
>
> New Batch: Scanning $a messages,
> 1       36153
> 2       8187
> 3       2188
> 4       767
> 5       319
> 6       139
> 7       70
> 8       45
> 9       18
> 10      11
> 11      17
> 12      6
> 13      4
> 14      3
> 15      5
>
> Found $a messages waiting
> 1       0
> 2       7545
> 3       7019
> 4       5126
> 5       3484
> 6       2535
> 7       1724
> 8       1238
> 9       915
> 10      618
> 11      489
> 12      372
> 13      260
> 14      211
> 15      161
>
> This surprised me. I was expecting the batch size to grow during busy
> periods. It seems that the batch size is generally a single message,
> even though more messages are waiting to be processed. Looking at log
> snippets in the mailing list archives confirms that this is common.
> Looking at the time distribution of (rather rare) larger batches I found
> these spread randomly over the day.
>
> We regularly get a peak in the incoming messages queue of a few
> thousands of messages. This makes me believe that there is not that much
> slack in the capacity. During these peaks the number of messages per
> batch does go up to the maximum.
>
> Is there a way to measure how many more messages per day a given system
> can take?
>
> Thanks for any ideas.
>
> Bart...
>
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