Recommendations for Bugzilla hardware

[Paulo Casanova]

Joel Peshkin Write:
> The conclusion I am starting to reach is that the IO bandwidth to your
MySQL databases > is the most critical function.

Although benchmarking is always interesting, this conclusion can be read on
almost every system design envolving SGBDs. Speeding up databases can be
almost always (yeah, if you run in a 33MHz 486 you'll probably have other
problems :)) reduced to speeding up I/O (reading and writing on typical OLTP
systems).

Standard database techniques will recommend RAID 0+1 (strip and mirror)
hardware managed naturally. Usually (under SCSI at least) this will give you
double throughput with half access time of each single disk. Main drawback
is that you *waste* 50% of the storage capacity. RAID 5 is more efficient in
terms of storage but slower.

BTW, we've got a server with > 100 users and about 30k bugs and a single
PIII 800MHz, 512Mb RAM and a SCSI disk can handle with *almost* no issues.
Not a formula-1 kind of performance but acceptable one. It all depends on
*what* your users are doing.

Best,
Paulo


-----Original Message-----
From: developers-owner at bugzilla.org [mailto:developers-owner at bugzilla.org]
On Behalf Of Joel Peshkin
Sent: quarta-feira, 19 de Outubro de 2005 2:27
To: developers at bugzilla.org
Subject: Re: Recommendations for Bugzilla hardware

Eddie Xie wrote:

>Hi, Kevin.  Thanks for your advice, but I think you're misunderstanding 
>the situation I'm in.  I'm not installing Bugzilla for the first time.  
>We already have over 100 users and 50,000 bugs.
>I want to migrate it to a larger system, and I wanted to know where to 
>direct our investment.
>
>If we could get a dual processor machine with each processor being 
>faster than the single processor we have now plus much more RAM plus a 
>bigger, faster, RAID system, then I know that the new system would be 
>faster, but I also know we'd be spending a lot of money that could more 
>usefully be spent elsewhere.  But where should the money be spent?
>I was trying to figure that out.
>
>  
>

We're still benchmarking, but we have found that the CPU load of even the
most intense operations does not make a dent in a dual-core AMD64, 4400
(that's 2200 per core with 1Mbyte/cache per core).  There is essentially no
swapping with 1GB of memory.  Note, here, that EVERYTHING (OS, Webserver,
Perl, MySQL) is compiled for 64-bit.

The identifiable botlenck is disk IO bandwidth.  Using 2 SATA channels to
implement a RAID0 (striping) array, the IO bandwidth is still the weak link
in the chain (though not very weak at all).  It seems that responsiveness is
still largely a function of the speed of single big queries rather than a
question of many concurrent operations.

The conclusion I am starting to reach is that the IO bandwidth to your MySQL
databases is the most critical function.



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