> · There are some columns set with TTL as X. After X Cassandra will > mark them as tombstones. Is there still a probability of running into > DistributedDeletes issue ? I understand that “distributeddeletes” is more > applicable to application deletes ? TTL'd columns are first turned into Tombstones and then purged after gc_grace.
> Nodetool repair will ask the neighbour node say node 2 to generate the > merkle tree. As I understand, currently the repair introduces 2 compactions. > Repairs currently require 2 major compactions: one to validate a column > family, and then another to send the disagreeing ranges. Will this be done > over the complete data set in the node 2 ? Or only for the range as per > Vnodes ? It only does one compaction. A Validation is used to create the merkle tree. Streaming differences is not done via compaction and only reads certain portions of files. It's done per token range. > · How does Cassandra do nodetool repair across Data centres ? Assume > RF=1 in DC1 and RF=1 in DC2 with total RF = 2 across the two DCs. No difference to all in the same DC. Cheers ----------------- Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 7/03/2013, at 2:04 PM, Kanwar Sangha <[email protected]> wrote: > Hi Guys – I have a question on Vnodes and nodetool repair. If I have > configured the nodes as vnodes, say for example 2 nodes with Rf=2. > > Questions – > > · There are some columns set with TTL as X. After X Cassandra will > mark them as tombstones. Is there still a probability of running into > DistributedDeletes issue ? I understand that “distributeddeletes” is more > applicable to application deletes ? > · Nodetool repair will ask the neighbour node say node 2 to generate > the merkle tree. As I understand, currently the repair introduces 2 > compactions. Repairs currently require 2 major compactions: one to validate a > column family, and then another to send the disagreeing ranges. Will this be > done over the complete data set in the node 2 ? Or only for the range as per > Vnodes ? > · How does Cassandra do nodetool repair across Data centres ? Assume > RF=1 in DC1 and RF=1 in DC2 with total RF = 2 across the two DCs. > > Thanks, > Kanwar >
