Yes, I already did a repair and cleanup. Currently my ring looks like this:
Address DC Rack Status State Load Owns Token ***.89 datacenter1 rack1 Up Normal 2.44 GB 50.00% 0 ***.135 datacenter1 rack1 Up Normal 6.99 GB 50.00% 85070591730234615865843651857942052864 It's not really a problem, but I'm still wondering why this happens. 2012/2/1 aaron morton <aa...@thelastpickle.com> > Do you mean the load in nodetool ring is not even, despite the tokens been > evenly distributed ? > > I would assume this is not the case given the difference, but it may be > hints given you have just done an upgrade. Check the system using nodetool > cfstats to see. They will eventually be delivered and deleted. > > More likely you will want to: > 1) nodetool repair to make sure all data is distributed then > 2) nodetool cleanup if you have changed the tokens at any point finally > > Cheers > > ----------------- > Aaron Morton > Freelance Developer > @aaronmorton > http://www.thelastpickle.com > > On 31/01/2012, at 11:56 PM, R. Verlangen wrote: > > 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 >>>> >>> >>> >>> >> >> >> > >
