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https://issues.apache.org/jira/browse/CASSANDRA-6218?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13835099#comment-13835099
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Lyuben Todorov commented on CASSANDRA-6218:
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If the local DC's name is missed out in the csv list supplied as a param then
an IllegalArgumentException is thrown, but to save us having to throw the
IllegalArgumentException n number of times (based on how many ranges the dc
has) we could cancel the repair.
A few tiny nits:
There are a few cases where the parenthesis are on the same line as the code
(should be on the next line)
{code}
// ActiveRepairService#getNeighbors
for (String dc : dataCenters) {
// StorageService#forceRepairAsync (overload 1)
public int forceRepairAsync(final String keyspace, final boolean isSequential,
final Collection<String> dataCenters, final boolean primaryRange, final
String... columnFamilies) {
// StorageService#forceRepairAsync (overload 2)
public int forceRepairAsync(final String keyspace, final boolean isSequential,
final Collection<String> dataCenters, final Collection<Range<Token>> ranges,
final String... columnFamilies) {
// StorageService#createRepairTask
if (isLocal) {
{code}
Also resources.o.a.c.cli.CliHelp.yaml should be updated to show the new *in_dc*
/ *in* param.
> Reduce WAN traffic while doing repairs
> --------------------------------------
>
> Key: CASSANDRA-6218
> URL: https://issues.apache.org/jira/browse/CASSANDRA-6218
> Project: Cassandra
> Issue Type: New Feature
> Components: Core, Tools
> Reporter: sankalp kohli
> Priority: Minor
> Fix For: 2.0.4
>
> Attachments: trunk-6218.txt
>
>
> The way we send out data that does not match over WAN can be improved.
> Example: Say there are four nodes(A,B,C,D) which are replica of a range we
> are repairing. A, B is in DC1 and C,D is in DC2. If A does not have the data
> which other replicas have, then we will have following streams
> 1) A to B and back
> 2) A to C and back(Goes over WAN)
> 3) A to D and back(Goes over WAN)
> One of the ways of doing it to reduce WAN traffic is this.
> 1) Repair A and B only with each other and C and D with each other starting
> at same time t.
> 2) Once these repairs have finished, A,B and C,D are in sync with respect to
> time t.
> 3) Now run a repair between A and C, the streams which are exchanged as a
> result of the diff will also be streamed to B and D via A and C(C and D
> behaves like a proxy to the streams).
> For a replication of DC1:2,DC2:2, the WAN traffic will get reduced by 50% and
> even more for higher replication factors.
>
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