Re: severe librbd performance degradation in Giant

[Mark Nelson <mark.nelson@inktank.com>]

On 09/17/2014 03:55 PM, Somnath Roy wrote:
> Hi Sage,
> We are experiencing severe librbd performance degradation in Giant over firefly release. Here is the experiment we did to isolate it as a librbd problem.
>
> 1. Single OSD is running latest Giant and client is running fio rbd on top of firefly based librbd/librados. For one client it is giving ~11-12K  iops (4K RR).
> 2. Single OSD is running Giant and client is running fio rbd on top of Giant based librbd/librados. For one client it is giving ~1.9K  iops (4K RR).
> 3. Single OSD is running latest Giant and client is running Giant based ceph_smaiobench on top of giant librados. For one client it is giving ~11-12K  iops (4K RR).
> 4. Giant RGW on top of Giant OSD is also scaling.
>
>
> So, it is obvious from the above that recent librbd has issues. I will raise a tracker to track this.

Hi Somnath,

How much concurrency?

>
> Thanks & Regards
> Somnath
>
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