It repairs the ranges they have in common. Cheers
----------------- Aaron Morton Freelance Developer @aaronmorton http://www.thelastpickle.com On 20/05/2012, at 4:05 PM, Raj N wrote: > Can I infer from this that if I have 3 replicas, then running repair without > -pr won 1 node will repair the other 2 replicas as well. > > -Raj > > On Sat, Apr 14, 2012 at 2:54 AM, Zhu Han <han...@nutstore.net> wrote: > > On Sat, Apr 14, 2012 at 1:57 PM, Igor <i...@4friends.od.ua> wrote: > Hi! > > What is the difference between 'repair' and '-pr repair'? Simple repair touch > all token ranges (for all nodes) and -pr touch only range for which given > node responsible? > > > -pr only touches the primary range of the node. If you executes -pr against > all nodes in replica groups, then all ranges are repaired. > > > On 04/12/2012 05:59 PM, Sylvain Lebresne wrote: > On Thu, Apr 12, 2012 at 4:06 PM, Frank Ng<buzzt...@gmail.com> wrote: > I also noticed that if I use the -pr option, the repair process went down > from 30 hours to 9 hours. Is the -pr option safe to use if I want to run > repair processes in parallel on nodes that are not replication peers? > There is pretty much two use case for repair: > 1) to rebuild a node: if say a node has lost some data due to a hard > drive corruption or the like and you want to to rebuild what's missing > 2) the periodic repairs to avoid problem with deleted data coming back > from the dead (basically: > http://wiki.apache.org/cassandra/Operations#Frequency_of_nodetool_repair) > > In case 1) you want to run 'nodetool repair' (without -pr) against the > node to rebuild. > In case 2) (which I suspect is the case your talking now), you *want* > to use 'nodetool repair -pr' on *every* node of the cluster. I.e. > that's the most efficient way to do it. The only reason not to use -pr > in this case would be that it's not available because you're using an > old version of Cassandra. And yes, it's is safe to run with -pr in > parallel on nodes that are not replication peers. > > -- > Sylvain > > > thanks > > > On Thu, Apr 12, 2012 at 12:06 AM, Frank Ng<berryt...@gmail.com> wrote: > Thank you for confirming that the per node data size is most likely > causing the long repair process. I have tried a repair on smaller column > families and it was significantly faster. > > On Wed, Apr 11, 2012 at 9:55 PM, aaron morton<aa...@thelastpickle.com> > wrote: > If you have 1TB of data it will take a long time to repair. Every bit of > data has to be read and a hash generated. This is one of the reasons we > often suggest that around 300 to 400Gb per node is a good load in the > general case. > > Look at nodetool compactionstats .Is there a validation compaction > running ? If so it is still building the merkle hash tree. > > Look at nodetool netstats . Is it streaming data ? If so all hash trees > have been calculated. > > Cheers > > > ----------------- > Aaron Morton > Freelance Developer > @aaronmorton > http://www.thelastpickle.com > > On 12/04/2012, at 2:16 AM, Frank Ng wrote: > > Can you expand further on your issue? Were you using Random Patitioner? > > thanks > > On Tue, Apr 10, 2012 at 5:35 PM, David Leimbach<leim...@gmail.com> > wrote: > I had this happen when I had really poorly generated tokens for the > ring. Cassandra seems to accept numbers that are too big. You get hot > spots when you think you should be balanced and repair never ends (I think > there is a 48 hour timeout). > > > On Tuesday, April 10, 2012, Frank Ng wrote: > I am not using tier-sized compaction. > > > On Tue, Apr 10, 2012 at 12:56 PM, Jonathan Rhone<rh...@tinyco.com> > wrote: > Data size, number of nodes, RF? > > Are you using size-tiered compaction on any of the column families > that hold a lot of your data? > > Do your cassandra logs say you are streaming a lot of ranges? > zgrep -E "(Performing streaming repair|out of sync)" > > > On Tue, Apr 10, 2012 at 9:45 AM, Igor<i...@4friends.od.ua> wrote: > On 04/10/2012 07:16 PM, Frank Ng wrote: > > Short answer - yes. > But you are asking wrong question. > > > I think both processes are taking a while. When it starts up, > netstats and compactionstats show nothing. Anyone out there successfully > using ext3 and their repair processes are faster than this? > > On Tue, Apr 10, 2012 at 10:42 AM, Igor<i...@4friends.od.ua> wrote: > Hi > > You can check with nodetool which part of repair process is slow - > network streams or verify compactions. use nodetool netstats or > compactionstats. > > > On 04/10/2012 05:16 PM, Frank Ng wrote: > Hello, > > I am on Cassandra 1.0.7. My repair processes are taking over 30 > hours to complete. Is it normal for the repair process to take this long? > I wonder if it's because I am using the ext3 file system. > > thanks > > > > > -- > Jonathan Rhone > Software Engineer > > TinyCo > 800 Market St., Fl 6 > San Francisco, CA 94102 > www.tinyco.com > > > > >
