Re: production ready?

[Stefan Priebe <s.priebe@profihost.ag>]

Am 30.10.2012 14:45, schrieb Gregory Farnum:
>> But there's still the problem of slow random write IOP/s. At least i haven't
>> seen any good benchmarks.
>
> It's not magic — I haven't done extensive testing but I believe people
> see aggregate IOPs of about what you can calculate:
> (number of storage disks * IOPS per disks) / (replication level)
> The journaling bumps that up a little bit for bursts, of course;
> similarly if you're doing it on a brand new RBD image it can be a bit
> slower since you need to create all the objects as well as write data
> to them. You need to architect your storage system to match your
> requirements. If you want to run write-heavy databases on RBD, there
> are people doing that. They're using SSDs and are very pleased with
> its performance. *shrug*

My last test was with 0.49 so i can't talk about 0.52 but as far as i 
know nothing has changed in this case.

I had 6 Dedicated servers running each with 4x Intel 520series SSDs 
running 4 OSDs (one OSD per disk). I had the journal running in tmpfs 
1GB size to be sure it isn't the bottleneck. Replication was set to 2.

Each SSD is capable of doing 30.000 IOP/s random 4k.

But with RBD i wasn't able to get more than 20.000 IOP/s but overall i had:
6 ded. servers * 4 SSDS => 24 OSDs/SSDs * 30.000 IOP/s / Replication 2 
=> 360.000 iop/s theoretical overall performance

But i didn't get more than 20.000 while using 3.6Ghz Xeon CPUs and Dual 
10GBE.

Greets,
Stefan
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