Hi Dieter, On Thu, 25 Sep 2014, Kasper Dieter wrote: > Hi Sage, > > I'm definitely interested in joining this weekly call starting Oct 1st. > Thanks for this initiative! Great! Please add these notes to http://pad.ceph.com/p/performance_weekly > Especially I'm interested in: > - how can we reduce the number of threads in the system > -- including to avoid the context switches in between > -- including to avoid the queues and locks in between You should take a look at Haomai's AsyncMessenger implementation he posted a few weeks back. I'm not sure how much testing it's seen, but it essentially refactors SimpleMessenger into a state machine and uses libevent to schedule work. > - how we can reduce the number of lines of code > -- including the multiple system calls for each IO I have some planned changes to ObjectStore::Transaction that make it handle-based. This will make it easier to cache and avoid lots of dup lookups (and lay some of the groundwork for the proposed KeyFileStore). > - how we can introduce a high efficient timestamp collection of the most important FN check-points > (see for example the attached file) > to measure the change and effect of our actions I think most of us are looking to LTTng or systemtap for this. You should also check out the thread '?nstrumenting RADOS with Zipkin + LTTng' from several weeks ago for a pretty promising tracing strategy. sage > > Best Regards, > -Dieter > > > On Thu, Sep 25, 2014 at 08:27:00PM +0200, Sage Weil 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 > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
