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From Ian Kluft <ikl...@cisco.com>
Subject Re: problem with status w/ 1.3b5
Date Fri, 20 Feb 1998 10:24:26 GMT
> From: Dean Gaudet <dgaudet@arctic.org>
> On Thu, 19 Feb 1998, Nathan Neulinger wrote:
> > On another note, is there some reason that the status module always 
> > displays the IP address for the current (me displaying the status) 
> > request? It looks like perhaps the DNS resolution is happening after the 
> > status request is getting handled. Is this intentional?
> 
> Intentional. 

That's not the whole story - there's some valuable info for other readers
to take note of... this is one case where an optimization is achieved by
defering an action until after the request has completed and disconnected.
Basically, if it doesn't have to be done while the user is waiting, save
it for after the connection when they won't notice.

For all you know, any given request could be from a benchmarking tool, or
just a user who cares how long it takes.  It's one of several approaches
that has achieved the performance that Apache is known for.

BTW, DNS requests are especially bad about this.  Depending on conditions
Apache has no control over, they can take almost forever to time out.
You definitely don't want to do that while the user's waiting!  But even
under ideal DNS circumstances, the optimization is still worthwhile.

If you work on other modules, you'd do well to follow this approach as well.
This isn't just for the core...
-- 
Ian Kluft  KO6YQ PP-ASEL                                  Cisco Systems, Inc.
ikluft@cisco.com (work)  ikluft@thunder.sbay.org (home)          San Jose, CA

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