[CASSANDRA-19489] Guardrail to warn clients about possible transient incorrect responses for filtering queries against multiple mutable columns

• Type: Improvement
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 5.0.x, 5.1
• Component/s: Consistency/Coordination, CQL/Semantics, Messaging/Client
• Change Category: Operability
• Complexity: Low Hanging Fruit
• Platform: All

Source Control Link

https://github.com/apache/cassandra/commit/be507c6e996078011c08e36b09d9f34faa454973#diff-41cce7fa5999d0a5fec7205180d9795d936d687200e269574b8bb95aa7937796

Test and Documentation Plan

There are new tests here around the new guardrail. They borrow a bit from the existing in-JVM GuardrailTester work.

• Assignee: Caleb Rackliffe
• Reporter: Caleb Rackliffe

Authors

Caleb Rackliffe

Reviewers

Berenguer Blasi, David Capwell

• Created: 22/Mar/24 18:59
• Updated: 03/Apr/24 21:49
• Resolved: 03/Apr/24 21:49

Description

Given we may not have time to fully resolve CASSANDRA-19007 before we release 5.0, it would still be helpful to have, at the very minimum, a client warning for cases where a user filters on two or more mutable (static or regular) columns at consistency levels that require coordinator reconciliation. We may also want the option to fail these queries outright, although that need not be the default.

The only art involved in this is deciding what we want to say in the warning/error message. It's probably reasonable to mention there that this only happens when we have unrepaired data. It's also worth noting that SAI queries are no longer vulnerable to this after the resolution of CASSANDRA-19018.

Issue Links

• links to: GitHub Pull Request #3220
• links to: GitHub Pull Request #3226