On Fri, Aug 2, 2019 at 6:57 PM Robert LeBlanc <rob...@leblancnet.us> wrote:
>
> On Fri, Jul 26, 2019 at 1:02 PM Peter Sabaini <pe...@sabaini.at> wrote:
>>
>> On 26.07.19 15:03, Stefan Kooman wrote:
>> > Quoting Peter Sabaini (pe...@sabaini.at):
>> >> What kind of commit/apply latency increases have you seen when adding a
>> >> large numbers of OSDs? I'm nervous how sensitive workloads might react
>> >> here, esp. with spinners.
>> >
>> > You mean when there is backfilling going on? Instead of doing "a big
>>
>> Yes exactly. I usually tune down max rebalance and max recovery active
>> knobs to lessen impact but still I found the additional write load can
>> substantially increase i/o latencies. Not all workloads like this.
>
>
> We have been using:
>
> osd op queue = wpq
> osd op queue cut off = high
>
> It virtually eliminates the impact of backfills on our clusters. Our backfill 
> and recovery times have increased when the cluster has lots of client I/O, 
> but the clients haven't noticed that huge backfills have been going on.
>
> ----------------
> Robert LeBlanc
> PGP Fingerprint 79A2 9CA4 6CC4 45DD A904  C70E E654 3BB2 FA62 B9F1
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Would this be superior to setting:

osd_recovery_sleep = 0.5 (or some high value)


--
Alex Gorbachev
Intelligent Systems Services Inc.
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