Murray,

You may remember that I have been complaining about long times
it takes for a dkim-milter (with Postfix) to sign long messages.

The mystery has now been explained, it is due to a deadlock
between a sender's Nagle algorithm and receivers's delayed ACK
policy. At each deadlock the session stalls for 0.1 seconds.

The problem is avoided in a sendmail setup because sendmail
uses larger buffer for sending mail contents to a milter,
which doesn't trigger TCP congestion avoidance mechanisms.

The problem is being addressed. See a thread starting at:
  http://marc.info/?l=postfix-users&m=118546060709676
  http://marc.info/?l=postfix-users&m=118547823903681

also:
  http://www.sigcomm.org/ccr/archive/2001/jan01/ccr-200101-mogul.pdf

Mark

-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >>  http://get.splunk.com/
_______________________________________________
dkim-milter-discuss mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/dkim-milter-discuss

Reply via email to