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@xxxxxxxxxx> 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@xxxxxxxxxxxxxxx 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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