mysql performance on 4 * dualcore opteron

Michael Vince mv at
Sat Apr 8 09:44:41 UTC 2006

David Xu wrote:

>ÔÚ Thursday 06 April 2006 17:12£¬Michael Vince дµÀ£º
>>I have also done benchmarking with libthr against Apache using 'ab' and 
>>found it can deliver an extra amount of megabytes/sec of data (I think 
>>it was about an extra 2000/requests sec) at the cost of giving the 
>>server from what I remember almost double the 'average load' according 
>>to 'top'
>>Given that if your machine has nothing else to do but deliver data 
>>purely from Apache then even libthr is more worth while for Apache as well.
>libpthread default uses M:N threads which means a thread  may be on
>userland scheduler's run queue, and FreeBSD kernel does not know, 
>so it will be not shown on average load, default system tools are not
>very useful here.
>David Xu
Yeah I figured that, which isn't fair because it makes pthread look 
better then libthr when its not.

I did notice that during the tests that when benchmarking Apache under 
libthr that when it was giving out the extra megabytes/sec speed that 
the server did feel equally responsive even though 'top' was reporting 
higher load.

I have also tried putting my Perl under libthr for a single thread log 
analyzer and to my surprise it even could process logs faster.

libthr is also really useful for actually paying attention to tops 'thr' 
column since it does show actual true thread number activity, under 
pthread it shows a couple and under libc_r I could have 1000 threads 
going but top just shows 1.


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