incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From aaron morton <aa...@thelastpickle.com>
Subject Re: VNodes and nodetool repair
Date Mon, 11 Mar 2013 13:17:34 GMT
> ·        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 <kanwar@mavenir.com> 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
>  


Mime
View raw message