If I understand the way replication is done, the node in us-east-1d has all the (data) replicas, right?
No, for this to be correct, you'd need to have one DC per AZ, which is not this case since you have a single DC encompassing multiple AZs. Right now, replicas will be spread in 3 distinct AZs, which are represented as racks in the single NTS DC if you are using EC2*Snitch. So your best bet is probably to run repair -pr in all nodes. 2016-09-01 14:28 GMT-03:00 Li, Guangxing <guangxing...@pearson.com>: > Thanks for the info, Paulo. > > My cluster is in AWS, the keyspace has replication factor 3 with > NetworkTopologyStrategy in one DC which have 5 nodes: 2 in us-east-1b, 2 in > us-east-1c and 1 in us-east-1d. If I understand the way replication is > done, the node in us-east-1d has all the (data) replicas, right? If so, if > I do not use '-pr' option, would it be enough to run 'nodetool repair' ONLY > on the node in us-east-1d? In other words, does 'nodetool repair' started > on node in us-east-1d also cause repairs on replicas on other nodes? I am > seeing different answers in discussion like this http://dba.stackexchange. > com/questions/82414/do-you-have-to-run-nodetool-repair-on-every-node. > > Thanks again. > > George > > On Thu, Sep 1, 2016 at 10:22 AM, Paulo Motta <pauloricard...@gmail.com> > wrote: > >> https://issues.apache.org/jira/browse/CASSANDRA-7450 >> >> 2016-09-01 13:11 GMT-03:00 Li, Guangxing <guangxing...@pearson.com>: >> >>> Hi, >>> >>> I have a cluster running 2.0.9 with 2 data centers. I noticed that >>> 'nodetool repair -pr keyspace cf' runs very slow (OpsCenter shows that the >>> node's data size is 39 GB and the largest SSTable size is like 7 GB so the >>> column family is not huge, SizeTieredCompactionStrategy is used). Repairing >>> a column family on a single node takes over 5 hours. So I am wondering if I >>> can use option '-local' and '-pr' together, hoping to get some speed up. >>> But according to documentation at https://docs.datastax.com/e >>> n/cassandra/2.0/cassandra/tools/toolsRepair.html '...Do not use -pr >>> with this option to repair only a local data center...'. Can someone tell >>> me the reason why we should not use options '-local' and '-pr' together? >>> >>> Thanks. >>> >>> George >>> >> >> >
