[CASSANDRA-18424] Implement graceful paging across tombstones with short-circuit on paging rather than throwing TombstoneOverwhelmingExceptions

• Type: New Feature
• Status: Triage Needed
• Priority: Normal
• Resolution: Unresolved
• Component/s: Messaging/Client, Messaging/Internode
• Platform: All
• Assignee: Josh McKenzie
• Reporter: Josh McKenzie

Authors

Josh McKenzie

• Created: 04/Apr/23 18:26
• Updated: 26/May/23 14:19

Description

We implemented the hard stop with a TombstoneOverwhelmingException almost a decade ago since paging across many tombstones was the most common way for nodes to OOM as they iterated across all this data during queries and paging.

With our current implementations and architecture / codebase, we should be able to combine the StoppingTransformation and existing clustering blob we pass back to clients to allow clients to optionally page across tombstones when using the async api via the driver and short-circuit a page when they hit the tombstone failure threshold rather than throwing a TombstoneOverwhelmingException. This would allow for more flexible data modeling on users' side as well as removing one of the fairly rough edges of our API's we're currently constrained by.

Making sure this is correct will require extensive fuzz-testing of pagination; this should likely happen in the Harry project but we could also have a bespoke model / implementation in the C* codebase we rely on in the interim.

Client warnings at the current default levels would remain; the gap between warn and "short-circuit pages" (100x ratio currently, 1000 vs. 100000) should  be sufficient for clients to take action on their data models well before they hit this limit.