Re: Weekly performance meeting

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

On 09/25/2014 09:47 PM, Guang Yang wrote:
> Hi Sage,
> We are very interested to join (and contribute effort) as well. Following are a list of issues we have particular interests:
>   1> Large number of small files bring performance degradation most due to file system lookup (even worst with EC).

Have you tried decreasing vfs_cache_pressure to retain dentries and 
inodes in cache?  I've had good luck improve performance for medium 
sized IO workloads doing this.

>   2> Messenger uses too many threads which bring burden for high density hardware (which I believe Haomai already has great progress).

Yes, The biggest thing on my personal wish list has been to move to a 
hybrid threading/event processing model.

>
> Thanks,
> Guang
>
> On Sep 26, 2014, at 2:27 AM, Sage Weil <sweil@redhat.com> wrote:
>
>> Hi everyone,
>>
>> A number of people have approached me about how to get more involved with
>> the current work on improving performance and how to better coordinate
>> with other interested parties.  A few meetings have taken place offline
>> with good results but only a few interested parties were involved.
>>
>> Ideally, we'd like to move as much of this dicussion into the public
>> forums: ceph-devel@vger.kernel.org and #ceph-devel.  That isn't always
>> sufficient, however.  I'd like to also set up a regular weekly meeting
>> using google hangouts or bluejeans so that all interested parties can
>> share progress.  There are a lot of things we can do during the Hammer
>> cycle to improve things but it will require some coordination of effort.
>>
>> Among other things, we can discuss:
>>
>> - observed performance limitations
>> - high level strategies for addressing them
>> - proposed patch sets and their performance impact
>> - anything else that will move us forward
>>
>> One challenge is timezones: there are developers in the US, China, Europe,
>> and Israel who may want to join.  As a starting point, how about next
>> Wednesday, 15:00 UTC?  If I didn't do my tz math wrong, that's
>>
>>   8:00 (PDT, California)
>> 15:00 (UTC)
>> 18:00 (IDT, Israel)
>> 23:00 (CST, China)
>>
>> That is surely not the ideal time for everyone but it can hopefully be a
>> starting point.
>>
>> I've also created an etherpad for collecting discussion/agenda items at
>>
>> 	http://pad.ceph.com/p/performance_weekly
>>
>> Is there interest here?  Please let everyone know if you are actively
>> working in this area and/or would like to join, and update the pad above
>> with the topics you would like to discuss.
>>
>> Thanks!
>> sage
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>