Jordan West created CASSANDRA-16285:
---------------------------------------
Summary: Change Dynamic Snitch Default Badness Threshold to 1.0
Key: CASSANDRA-16285
URL: https://issues.apache.org/jira/browse/CASSANDRA-16285
Project: Cassandra
Issue Type: Improvement
Components: Consistency/Coordination
Reporter: Jordan West
Assignee: Jordan West
Attachments: readcount-0.1.png, readcount-1.0.png,
readlatency-0.1.png, readlatency-1.0.png
With the removal of compaction and IO from the DynamicEndpointSnitch score
calculation, the default badness threshold of 10% (0.1) is too small of a
margin from experience with production clusters. When compaction and IO values
were included, the resulting scores were dominated by them and 10% was a much
more noticeable difference. When relying solely on latency, the
DynamicEndpointSnitch can rely on nodes that are performing only marginally
better than their peers. This results in a lopsided request distribution among
the replicas despite similar performance.
Some graphs are attached from a production cluster showing the read count and
latency among the nodes with the default of 0.1 and with the badness threshold
set to 1.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
