[CASSANDRA-18563] Convert AccordStateCache cache from write-through to write-back

• Type: Improvement
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 5.0-alpha1, 5.0
• Component/s: Accord
• Epic Link: CEP-15: Accord Beta
• Change Category: Performance
• Complexity: Normal
• Platform: All

Source Control Link

https://github.com/apache/cassandra/commit/bd33015f9310e15c7f7e6b3938f564dd20050466

Test and Documentation Plan

unit tests

• Assignee: Aleksey Yeschenko
• Reporter: Aleksey Yeschenko

Authors

Aleksey Yeschenko

Reviewers

Blake Eggleston

• Created: 02/Jun/23 12:22
• Updated: 12/Sep/23 13:03
• Resolved: 16/Jun/23 14:20

Description

Pre-requisite work for soon to go up PRs that continue shifting the bulk of persistence from system tables to AccordJournal. The switch to write-back caching should allow to bypass writes to the system tables entirely for some of the transactions.

Additionally fixes some bugs in the cache, e.g. AsyncLoader failing to load an object could cause entries to be forever stuck in PENDING state because it would never reach the code path that submits the load runnables to the executor (that is now the job of the cache). Also switched the list implementation from a hand-rolled ad-hoc one to the pre-existing IntrusiveLinkedList, plus various simplifications and cleanup.