[CASSANDRA-2389] Send writes to stable replicas when replicate-on-write is disabled during bootstrap

• Type: Bug
• Status: Resolved
• Priority: Low
• Resolution: Won't Fix
• Severity: Low
• Assignee: Stu Hood
• Reporter: Stu Hood

Authors

Stu Hood

Reviewers

Sylvain Lebresne

• Created: 25/Mar/11 21:27
• Updated: 16/Apr/19 09:33
• Resolved: 25/Jan/13 20:49

Description

During bootstrap with replicate-on-write disabled, our previous approach of widening the replica set via TokenMetadata.getWriteEndpoints is not the correct approach. Instead, since a write is not immediately bound for all replicas, it needs to be sent to a replica that isn't joining or leaving the replica set due to bootstrap.

Example: with rf=3, 4 nodes are active in a particular replica set: 1 is joining the set, 1 is leaving the set, and 2 are stable in the set (not affected by the bootstrap). The 2 stable nodes are the ones to which it is "safe" to send un-replicated writes during the bootstrap.

Note that running without replicate-on-write enabled is never recommended, but while the setting exists, we should do the right thing.

Issue Links

• is related to: CASSANDRA-2397 Improve or remove replicate-on-write setting