amavisd 2.7.0 and Mail::OpenDKIM

[Mark Martinec]

Quanah,

> Will Amavisd 2.7.0 have support for using Mail::OpenDKIM as an alternative
> to Mail::DKIM?  The performance numbers between the two are certainly
> striking, and I think it would be worthwhile to have the flexibility to
> choose which one I wanted to use with Amavisd.

Striking indeed - see the table below!

Shown is elapsed time for reading a mail from a temporary file,
feeding it into the signer and generating a signature (using
the same Perl code section as used by amavisd for signing a
mail, relaxed/simple, rsa-sha256):

mail size Mail::DKIM OpenDKIM
--------- ---------- --------
0.1 MB      8.8 ms    11.8 ms
1 MB       29 ms      32 ms
5 MB      115 ms     121 ms
10 MB     222 ms     231 ms

which gives about 40 MB/s processing rate for large mail,
with some fixed overhead. Amazingly the Mail::DKIM has
a small but consistent edge over Mail::OpenDKIM,
not to mention that it lacks plenty of functionality.

Don't know how they did their benchmarking. Perhaps
they tried to feed a message to a signer line-by-line,
which is a recipe for performance disaster.
Amavis does it by 16 kB chunks.

  Mark