Read Repair behavior thwards DynamicEndpointSnitch at CL.ONE ------------------------------------------------------------
Key: CASSANDRA-1873 URL: https://issues.apache.org/jira/browse/CASSANDRA-1873 Project: Cassandra Issue Type: Bug Components: Core Reporter: Jonathan Ellis Fix For: 0.6.9, 0.7.1 When doing a CL.ONE read, the coordinator node selects the data node from the list of replicas via snitch sortByProximity. The data node (_not_ the coordinator) then sends digest requests to the remaining replicas, and compares their answers to its own (in ConsistencyChecker). This means that, in a multi-datacenter situation, for any given range R with replicas X in dc1 and Y in dc2, the only node with latency information for Y will be X. Since DES falls back to subsnitch (static) order when latency information is missing for any replica it is asked to sort, DES will be unable to direct requests to Y no matter how overwhelmed X becomes. To fix this, we should move the digest-checking code into the coordinator node (probably starting with the 0.7 ConsistencyChecker, which represents a cleanup of the 0.6 one). -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.