The issue you saw is now HBASE-2022. J-D
On Tue, Dec 1, 2009 at 7:50 AM, Zhenyu Zhong <[email protected]> wrote: > So far I have been using gchisto to view the gc-log. > In my last RS disconnection, I saw a total GC about 457 seconds. But > individually, the max is 1340 ms, min is 0.527ms, avg is 48ms. > > The RS disconnection might be due to other reasons. I think J-D has been > digging that. > > thanks > zhenyu > > > > On Mon, Nov 30, 2009 at 9:22 PM, stack <[email protected]> wrote: > >> I suppose up to this I thought it a given for any java application that >> wants to do realtime whether a webserver or search application but yeah, we >> should do more to highlight the import of GC tuning especially when failure >> to do so can be relatively catastrophic (A RegionServer self-shutting >> itself >> down). Ryan in particular has been doing a bunch of talking up of the >> topic >> (He did our performance tuning wiki page too). We could start up a list >> of >> use cases and the tunings that helped alleviate GC woes for a particular >> cluster profile and loading (So we'd have something to present at BAHUG? >> Do >> you know who we might talk to regards pauses in the MR/HDFS team Patrick? >> We were introduced to the NameNode Tuner once... we should talk to him >> again). It does seem to be a problem where one tuning does not suit all >> deploys. >> >> Regards Zhenyu's case, there is still work to do IMO. What I saw in his >> logs was a failed promotion from parnew, something that could be helped >> starting CMS collection earlier (among other things). Hes also still on an >> older version of the JVM. While things are not timing out at the moment, >> IMO its still 'broke' if it has such long pauses (Zhenyu, in your GC logs, >> are you seeing 4 minutes pause?). Ryan would argue these are inevitable >> with CMS -- but at least in the one case that I saw some twiddling would >> seem to help. >> >> Thanks Patrick, >> St.Ack >> >
