Re: Why facebook used mysql ?

On Tue, Nov 9, 2010 at 1:36 PM, Sandeep Srinivasa <sss(at)clearsenses(dot)com>wrote:

>
> On Tue, Nov 9, 2010 at 11:46 PM, David Boreham <david_list(at)boreham(dot)org>wrote:
>>
>>
>> Hmm...typically multi-core scaling issues are in the area of memory
>> contention and cache coherence (and therefore are for the most part not
>> dependent on the OS and its scheduler).
>
>
> If it is independent of the OS, then how does one go about tuning it.
>
> Consider this - I get a 12 core server on which I want multiple webserver
> instances + DB. Can one create CPU pools (say core 1,2,3 for webservers,
> 4,5,6,7 for DB, etc.) ?
>
> I know about taskset, but should one be using it ?
>
>
You can do this in some systems (we've done it on solaris systems for
example), but realize that for any of the high scale websites, they run
dedicated machines for database and web services; and that's essentially a
mandatory requirement just for purposes of having visibility into what is
affecting your server performance at scale.

It might also be worth mentioning that Facebook doesn't actually run MySQL
like you'd get from Oracle; they have their own custom patch set that is
tuned specifically for their servers (based on their OS modifications as
well). Probably the closest equivalent would be Percona's XtraDB table
engine, and I have seen some benchmarks that would certainly show comparable
performance at 32 cores if not slightly better, but of course it will be
somewhat workload dependent. It's mostly irrelevant though to "internet
oriented" companies, very few are looking for 32+ core systems as a solution
to their problems.

Robert Treat
play: http://www.xzilla.net
work: http://www.omniti.com/is/hiring