debugging the server on OS X

Evan Martin martine at
Fri Nov 26 10:47:55 PST 2004

On Tue, Nov 23, 2004 at 01:34:02PM -0800, Sean Chittenden wrote:
> >Can you suggest where I should perhaps add further debug statements to 
> >the server code to try to find the delay?
> It's most certainly a libevent(3) "problem."  kqueue(2) on OS-X is 
> crippled from what I can tell.  I think (though I haven't tested this) 
> that if you used poll(2) or even select(2), you'd get better 
> performance.  There are some environment variables that libevent(3) 
> listens to in order to choose what event method to use.  Now, if 
> changing that doesn't fix things, then it's probably a problem with 
> OS-X's TCP_NOPUSH implementation.  :(  -sc

I just wanted to confirm I've also seen terrible speed problems on OS X,
and as I recall it was even with select.  It's either a bug with how
memcached uses libevent, or how libevent uses select, or...

(This was many months ago, though...)

Evan Martin
martine at

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