Use DCAwareRoundRobinPolicy as fallback for TokenAwarePolicy #1285
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
- Previously, RoundRobinPolicy would attempt cross-dc writes Signed-off-by: Prithvi Raj <[email protected]>
vprithvi
requested review from
black-adder,
jpkrohling,
objectiser,
pavolloffay,
tiffon and
yurishkuro
as code owners
ghost
assigned 
black-adder
approved these changes
Jan 16, 2019
| if c.LocalDC != "" { | ||
| fallbackHostSelectionPolicy = gocql.DCAwareRoundRobinPolicy(c.LocalDC) | ||
| } | ||
| cluster.PoolConfig.HostSelectionPolicy = gocql.TokenAwareHostPolicy(fallbackHostSelectionPolicy, gocql.ShuffleReplicas()) |
There was a problem hiding this comment.
what does gocql.ShuffleReplicas() do?
There was a problem hiding this comment.
There can be multiple replicas (equal to RF) for a given token. ShuffleReplicas selects one of these replicas at random instead of deterministically selecting a replica.
yurishkuro
approved these changes
Jan 16, 2019
plugin/storage/cassandra/options.go
Outdated
| flagSet.String( | ||
| nsConfig.namespace+suffixDC, | ||
| nsConfig.LocalDC, | ||
| "The Cassandra local data center for DC Aware host selection") |
There was a problem hiding this comment.
The Cassandra name of local data center...
Signed-off-by: Prithvi Raj <[email protected]>
Codecov Report
@@ Coverage Diff @@
## master #1285 +/- ##
========================================
Coverage ? 100%
========================================
Files ? 161
Lines ? 7198
Branches ? 0
========================================
Hits ? 7198
Misses ? 0
Partials ? 0
Continue to review full report at Codecov.
|
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Which problem is this PR solving?
Short description of the changes
DCAwareRoundRobinas a fallback forTokenAwareHostPolicy