Timeouts when submitting mail

Previous Topic Next Topic
 
classic Classic list List threaded Threaded
2 messages Options
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Timeouts when submitting mail

Stijn van der Ree
We've set up two servers (ssd raid/64GB/fast dual cpu) with postmulti to deliver the mail for our newsletter service (legitimate mail). Both servers have 12 postfix instances running. Mails is injected from php scripts running at a different server.

Lately we're seeing timeouts from the php scripts at busy moments. I've been trying to debug this, but can't find the issue. Some information:

- Mail is injected through smtp, port 25
- The active queue is almost empty, even at peak moments (qshape)
- Number of deferred mails is low
- I've set default_process_limit to 10000 and smtpd_client_connection_count_limit to 3000
- Load on the servers is never higher then 2
- Number of smtp processes peaks at about 2000
- We're running local DNS
- We're using opendkim to sign every message

What can I do to find the reason for the timeouts?

Thanks.
Reply | Threaded
Open this post in threaded view
|  
Report Content as Inappropriate

Re: Timeouts when submitting mail

Wietse Venema
svdr:
> What can I do to find the reason for the timeouts?

You need to find out where in the SMTP protocol the timeout happens.

- TCP connection setup.

- SMTP Server '220' initial response.

- EHLO, MAIL FROM, RCPT TO, DATA, end-of-data.

Ideally, the PHP client would provide that information.

Postfix logging will show 'lost connection after XXX', but that
happens only for a completed TCP connection.

        Wietse
Loading...