On January 16, 2010 9:39:26 AM -0500 Wietse Venema <wie...@porcupine.org>
wrote:
Frank Cusack:
until a name lookup has been done. But if that name lookup takes a
"very long" time, along with the connect postfix should log how long
ago the actual connect was.
The SMTP server can find out long the name/address lookup took.
Exactly my point ... and that it should (could) log that info if it
took a "long" time, so that timestamps on logs can be more easily
correlated across systems.
It does not juggle TCP packets.
I don't understand what you're saying here.
The sysadmin should have done those name/address lookups by hand
as part of due diligence, and would have observed the exact same
delays that Postfix experienced.
No, because typically both the resolver or intermediary (nscd et al)
on the system running the lookup will cache results, as will the
nameservers configured in resolv.conf. The sysadmin doing a lookup
will get different timing due to being presented cached results.
Even if we had TTLs of 0 (no caching; BTW not always honored by
nscd type caches), differing network conditions at the time of some
problem and the time of investigation could result in different
name lookup delays.
I amend my suggestion to say that postfix, if it wanted to log the
name lookup delay, should do it *always*, not just when the delay
is "excessive", for consistency in the log format.
-frank
