From: Wietse Venema (no email)
Date: Mon Mar 23 2009 - 19:42:28 EDT
> On Mon, Mar 23, 2009 at 07:24:50PM -0400, Wietse Venema wrote:
> > Victor Duchovni:
> > > and may be causing high disk latency. You have to tune the milter configuration
> > There is no need for dkim-milter to touch the disk. It receives
> > header and body content from Postfix via the Milter protocol. I
> > know this, because I implemented the Postfix side of the protocol.
> No need perhaps, but does that prove that no disk I/O takes place? I am
> not saying there is disk I/O, but lack of need is not lack of use. So
> that should be excluded. If the disk is not saturated, perhaps there
> are DNS lookups or other sources of latency.
dkim-milter does not store the email message outside the mail queue.
In signing mode, it receives the headers and body from Postfix,
and then it asks Postfix to add a message header with the DKIM
dkim-milter does not use DNS lookups while signing mail. It has
a copy of the private key.
dkim-milter does of course use DNS lookups when verifying signatures.
It is possible that he is running it in verify mode, and that his
DNS has a 13ms round-trip time over a slow 128kbps ADSL uplink.
But it seems unlikely.
> Tracing the system calls in the milter may help (when sending just
> one message to reduce confusion).
strace-ing a multi-threaded program, have fun.