After running 3 days on Cassandra 1.0.7 it seems the problem has been solved. One weird thing remains, on our 2 nodes (both 50% of the ring), the first's usage is just over 25% of the second.
Anyone got an explanation for that? 2012/1/29 aaron morton <aa...@thelastpickle.com> > Yes but… > > For every upgrade read the NEWS.TXT it will go through the upgrade > procedure in detail. If you want to feel extra smart scan through the > CHANGES.txt to get an idea of whats going on. > > Cheers > > ----------------- > Aaron Morton > Freelance Developer > @aaronmorton > http://www.thelastpickle.com > > On 29/01/2012, at 4:14 AM, Maxim Potekhin wrote: > > Sorry if this has been covered, I was concentrating solely on 0.8x -- > can I just d/l 1.0.x and continue using same data on same cluster? > > Maxim > > > On 1/28/2012 7:53 AM, R. Verlangen wrote: > > Ok, seems that it's clear what I should do next ;-) > > 2012/1/28 aaron morton <aa...@thelastpickle.com> > >> There are no blockers to upgrading to 1.0.X. >> >> A >> ----------------- >> Aaron Morton >> Freelance Developer >> @aaronmorton >> http://www.thelastpickle.com >> >> On 28/01/2012, at 7:48 AM, R. Verlangen wrote: >> >> Ok. Seems that an upgrade might fix these problems. Is Cassandra 1.x.x >> stable enough to upgrade for, or should we wait for a couple of weeks? >> >> 2012/1/27 Edward Capriolo <edlinuxg...@gmail.com> >> >>> I would not say that issuing restart after x days is a good idea. You >>> are mostly developing a superstition. You should find the source of the >>> problem. It could be jmx or thrift clients not closing connections. We >>> don't restart nodes on a regiment they work fine. >>> >>> >>> On Thursday, January 26, 2012, Mike Panchenko <m...@mihasya.com> wrote: >>> > There are two relevant bugs (that I know of), both resolved in >>> somewhat recent versions, which make somewhat regular restarts beneficial >>> > https://issues.apache.org/jira/browse/CASSANDRA-2868 (memory leak in >>> GCInspector, fixed in 0.7.9/0.8.5) >>> > https://issues.apache.org/jira/browse/CASSANDRA-2252 (heap >>> fragmentation due to the way memtables used to be allocated, refactored in >>> 1.0.0) >>> > Restarting daily is probably too frequent for either one of those >>> problems. We usually notice degraded performance in our ancient cluster >>> after ~2 weeks w/o a restart. >>> > As Aaron mentioned, if you have plenty of disk space, there's no >>> reason to worry about "cruft" sstables. The size of your active set is what >>> matters, and you can determine if that's getting too big by watching for >>> iowait (due to reads from the data partition) and/or paging activity of the >>> java process. When you hit that problem, the solution is to 1. try to tune >>> your caches and 2. add more nodes to spread the load. I'll reiterate - >>> looking at raw disk space usage should not be your guide for that. >>> > "Forcing" a gc generally works, but should not be relied upon (note >>> "suggest" in >>> http://docs.oracle.com/javase/6/docs/api/java/lang/System.html#gc()). >>> It's great news that 1.0 uses a better mechanism for releasing unused >>> sstables. >>> > nodetool compact triggers a "major" compaction and is no longer a >>> recommended by datastax (details here >>> http://www.datastax.com/docs/1.0/operations/tuning#tuning-compactionbottom >>> of the page). >>> > Hope this helps. >>> > Mike. >>> > On Wed, Jan 25, 2012 at 5:14 PM, aaron morton <aa...@thelastpickle.com> >>> wrote: >>> > >>> > That disk usage pattern is to be expected in pre 1.0 versions. Disk >>> usage is far less interesting than disk free space, if it's using 60 GB and >>> there is 200GB thats ok. If it's using 60Gb and there is 6MB free thats a >>> problem. >>> > In pre 1.0 the compacted files are deleted on disk by waiting for the >>> JVM do decide to GC all remaining references. If there is not enough space >>> (to store the total size of the files it is about to write or compact) on >>> disk GC is forced and the files are deleted. Otherwise they will get >>> deleted at some point in the future. >>> > In 1.0 files are reference counted and space is freed much sooner. >>> > With regard to regular maintenance, node tool cleanup remvos data from >>> a node that it is no longer a replica for. This is only of use when you >>> have done a token move. >>> > I would not recommend a daily restart of the cassandra process. You >>> will lose all the run time optimizations the JVM has made (i think the >>> mapped files pages will stay resident). As well as adding additional >>> entropy to the system which must be repaired via HH, RR or nodetool repair. >>> > If you want to see compacted files purged faster the best approach >>> would be to upgrade to 1.0. >>> > Hope that helps. >>> > ----------------- >>> > Aaron Morton >>> > Freelance Developer >>> > @aaronmorton >>> > http://www.thelastpickle.com >>> > On 26/01/2012, at 9:51 AM, R. Verlangen wrote: >>> > >>> > In his message he explains that it's for " Forcing a GC ". GC stands >>> for garbage collection. For some more background see: >>> http://en.wikipedia.org/wiki/Garbage_collection_(computer_science) >>> > Cheers! >>> > >>> > 2012/1/25 <mike...@thomsonreuters.com> >>> > >>> > Karl, >>> > >>> > Can you give a little more details on these 2 lines, what do they do? >>> > >>> > java -jar cmdline-jmxclient-0.10.3.jar - localhost:8080 >>> > java.lang:type=Memory gc >>> > >>> > Thank you, >>> > Mike >>> > >>> > -----Original Message----- >>> > From: Karl Hiramoto [mailto:k...@hiramoto.org] >>> > Sent: Wednesday, January 25, 2012 12:26 PM >>> > To: user@cassandra.apache.org >>> > Subject: Re: Restart cassandra every X days? >>> > >>> > >>> > On 01/25/12 19:18, R. Verlangen wrote: >>> >> Ok thank you for your feedback. I'll add these tasks to our daily >>> >> cassandra maintenance cronjob. Hopefully this will keep things under >>> >> controll. >>> > >>> > I forgot to mention that we found that Forcing a GC also cleans up some >>> > space. >>> > >>> > >>> > in a cronjob you can do this with >>> > http://crawler.archive.org/cmdline-jmxclient/ >>> > >>> > >>> > my cron >>> >> >> >> > > >
