Isn't there more to it than that. You really have nodes responsible for token ranges like so(using describe ring)
What we see is this from our describe ringŠ(1 to 6 are token ranges while A to F are servers)Š. A - 1, 2, 3 B - 2, 3, 4 C - 3, 4, 5 D - 4, 5, 6 E - 5, 6, 1 F - 6, 1, 2 With -pr, only token range 1 is repaired I think, right? 2 and 3 are only repaired without the -pr option? This means if I have a node that I just joined the cluster, I should "not" be using -pr as 2 and 3 on node A will not be up to date. Using -pr is nice if I am going to repair every single node and is nice for the cron job that has to happen before gc_grace_seconds. Am I wrong here? Ie. -pr is really only good for use in the cron job as it would miss 2 and 3 above. I could run the cron on just two servers but then my nodes are different which can be a hassle. Please verify that is what you believe is what happens as well? Thanks, Dean On 2/28/13 5:58 PM, "Takenori Sato(Cloudian)" <ts...@cloudian.com> wrote: >Hi, > >Please note that I confirmed on v1.0.7. > > > I mean a repair involves all three nodes and pushes and pulls data, >right? > >Yes, but that's how -pr works. A repair without -pr does more. > >For example, suppose you have a ring with RF=3 like this. > >A - B - C - D - E - F > >Then, a repair on A without -pr does for 3 ranges as follows: >[A, B, C] >[E, F, A] >[F, A, B] > >Among them, the first one, [A, B, C] is the primary range of A. > >So, with -pr, a repair runs only for: >[A, B, C] > > > I could run nodetool repair on just 2 nodes(RF=3) instead of using >nodetool repair pr??? > >Yes. > >You need to run two repairs on A and D. > > > What is the advantage of pr then? > >Whenever you want to minimize rapair impacts. > >For example, suppose you got one node down for a while, and bring it >back to the cluster. > >You need to run rapair without affecting the entire cluster. Then, -pr >is the option. > >Thanks, >Takenori > >(2013/03/01 7:39), Hiller, Dean wrote: >> Isn't it true if I have 6 nodes, I could run nodetool repair on just 2 >>nodes(RF=3) instead of using nodetool repair pr??? >> >> What is the advantage of pr then? >> >> I mean a repair involves all three nodes and pushes and pulls data, >>right? >> >> Thanks, >> Dean >
