FreeBSD MySQL still WAY slower than Linux

[Greg Barniskis]

J. T. Farmer wrote:
> Uzi wrote:
> 
>> [...]
>>
>>> super-smack select-key
>>>         5.4-RELEASE             ~20,000 queries/second
>>>         6.0-CURRENT             ~24,000 queries/second
>>>         CentOS w/async  ~36,000 queries/second
>>>         CentOS w/sync   ~26,000 queries/second
>>>
>>> super-smack update-select
>>>         5.4-RELEASE             ~4,000 queries/second
>>>         6.0-CURRENT             ~4,500 queries/second
>>>         CentOS w/async  ~7,500 queries/second
>>>         CentOS w/sync   ~750 queries/second
>>>
>>> That last CentOS number is not a typo, it was an order of magnitude 
>>> slower.  I didn't try other file systems on CentOS, just the default 
>>> ext3. It's possible that reiserfs or xfs might not be as affected by 
>>> switching from async to sync.
>>>
>>> So my production server is now happily running mysql 4.1 on 
>>> 6.0-CURRENT :).
>>
>>
>> I don't get it.
>> You get 30% less perfomance, running a non-production release for 
>> production, and happy about it?  
> 
> 
> 
> Try reading it again.  The last time I checked, 24k queries/sec _is_ 
> faster than
> 20k queries/sec.  And 4.5k queries/sec is faster than 4.0k queries/sec.

I think he meant comparing 36,000 on CentOS (async) to 24,000 on 
CURRENT (sync). I wondered that myself, and having searched out the 
answer I find that it is declared in

http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/configtuning-disk.html

that async provides fast writes at the cost of "no guarantee at all 
for a consistent state of the filesystem". So, you choose: fast but 
not so reliable writes, or slower writes with fast, reliable 
disaster recovery.

Thanks to the FreeBSD team for choosing the sensible default, even 
if it results in the occasional "Linux is faster!" debate. Dang 
smirky penguins... you're flightless I tell ya, flightless. =)


-- 
Greg Barniskis, Computer Systems Integrator
South Central Library System (SCLS)
Library Interchange Network (LINK)
<gregb at scls.lib.wi.us>, (608) 266-6348