[
https://issues.apache.org/jira/browse/CASSANDRA-2506?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13151185#comment-13151185
]
Sylvain Lebresne commented on CASSANDRA-2506:
---------------------------------------------
I want to note that this v3 doesn't handle the case in the description of this
ticket. Basically there has been 2 proposition of enhancements for RR on this
ticket:
# Being able to completely exlude a given DC of any RR
# Have a different chance of repair for intra-DC and inter-DC RR
The initial patch from Vijay was basically handling both. I only regretted that
this was resulting in something imo complicated for the user (but without
having a much better initiave to suggest).
Jonathan then proposed to only add a list of DC that would be excluded from RR.
This obviously only takle the 1st improvement above. The v3 chooses to only add
a local RR chance, which only tackle the 2nd improvement above.
I'm fine saying RR is still useful and needs DC-related improvements, but we
should first agree on what those are maybe.
On the patch itself:
* Still no handling of KW_DCLOCALREADREPAIRCHANCE in
CreateColumnFamilyStatement.java
* If there is not enough node in the local DC for blockfor and if the first
endpoints of the endpoint list are not (all) from the local DC (possible), then
we could end up no read repairing all the node from the local DC even if the
chance < DcLocalReadRepair.
> Push read repair setting down to the DC-level
> ---------------------------------------------
>
> Key: CASSANDRA-2506
> URL: https://issues.apache.org/jira/browse/CASSANDRA-2506
> Project: Cassandra
> Issue Type: New Feature
> Components: Core
> Affects Versions: 1.0.1
> Reporter: Brandon Williams
> Assignee: Vijay
> Priority: Minor
> Fix For: 1.0.4
>
> Attachments: 0001-dc-localized-read-repair-v2.patch,
> 0001-dc-localized-read-repair.patch, 0001-thrift-and-avro-changes-v3.patch,
> 0002-dc-localized-read-repair-v3.patch, 0002-thrift-and-avro-v2.patch,
> 0002-thrift-and-avro.patch, 0003-documentation-for-read_repair-v3.patch,
> 0003-documentation-for-read_repair_options-v2.patch,
> 0003-documentation-for-read_repair_options.patch
>
>
> Currently, read repair is a global setting. However, when you have two DCs
> and use one for analytics, it would be nice to turn it off only for that DC
> so the live DC serving the application can still benefit from it.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
