Re: Mail::OpenDKIM

From: Murray S. Kucherawy <msk_at_blackops.org>
Date: Tue, 14 Jun 2011 11:28:34 -0700 (PDT)

On Tue, 14 Jun 2011, Nigel Horne wrote:
> Mark's example hardly uses the Mail::OpenDKIM module, by which I mean
> the data goes straight through the Mail::OpenDKIM layer with little
> processing; most of the time he measures is spent within the OpenDKIM
> library. It is therefore better for one of the OpenDKIM library
> maintainers to talk about benchmark issues than me.
>
> [...]

Certainly calling any of the interfaces numerous times where a single call
to dkim_chunk() is sufficient will degrade performance.

The last time I did any profiling of the library in terms of performance,
most of the processing time fell on the openssl hashing and encryption
functions. I'll have to find some time (or help) to repeat that work to
see if something's crept in that slows us down. But if that's still the
case then I'm not sure what we could do to improve it.

The other data feed interface, using dkim_header(), dkim_eoh(),
dkim_body() and dkim_eom(), is slower but is meant to mimic the milter API
directly since that was the origin of the work. It's likely not as
performant.

Another drop happens when you use relaxed vs. simple, since there's an
extra layer of text processing that has to occur when using that
canonicalization. Further penalty occurs if any features are enabled that
cause I/O to occur (i.e., writing the canonicalized form to a temporary
file).

Anyway, I'll try to make some time for profiling work in the near future.

-MSK
Received on Tue Jun 14 2011 - 18:29:09 PST