> -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of [email protected] > Sent: Thursday, October 01, 2009 9:26 PM > To: rsyslog-users > Subject: Re: [rsyslog] DNS cache and expiration > > On Thu, 1 Oct 2009, Rainer Gerhards wrote: > > > I have now reviewed the discussion in depth. Many thanks > for all the good > > thoughts. > > > > I will now first begin to move the name resolution calls to > the "backend" > > threads (away from the inputs). However, I will create an > option that the > > name resolution may be done before enqueing the message, > which may be used by > > some folks for whatever reason (plus, it is trivially to > do). I also think I > > will leave in the capability that inputs do the name > resolution themselfs, at > > least if they prefer. For example, imuxsock always has the > local host as > > input, so it makes limited sense to do name resolution > calls for messages > > received from that input. Similarly, imtcp uses the name > that was (once) > > obtained when the session was created (btw, this is also > some expiry-less > > "name resolution", but I think here it is even harder to > argue against it > > ;)). > > on note on this, if you can delay the resolution to the point where > something actually accesses the property that uses the name > you may be > able to skip doing name resolution entirely in many cases.
This I plan to do, but in the TCP case I think it probably is better to do a name resolution once per *session* even if the name may never be used. Typically, there are many messages in a session and the overhead if the one name lookup does not really matter. At least this is my current thinking. Rainer _______________________________________________ rsyslog mailing list http://lists.adiscon.net/mailman/listinfo/rsyslog http://www.rsyslog.com
