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32e3a01718
Motivation ---------- Since strongly consistent tables are based on the concept of Raft groups, operations on them can get stuck for indefinite amounts of time. That may be problematic, and so we'd like to implement a way to cancel those operations at suitable times. Description of solution ----------------------- The situations we focus on are the following: * Timed-out queries * Leader changes * Tablet migrations * Table drops * Node shutdowns We handle each of them and provide validation tests. Implementation strategy ----------------------- 1. Auxiliary commits. 2. Abort operations on timeout. 3. Abort operations on tablet removal. 4. Extend `client_state`. 5. Abort operation on shutdown. 6. Help `state_machine` be aborted as soon as possible. Tests ----- We provide tests that validate the correctness of the solution. The total time spent on `test_strong_consistency.py` (measured on my local machine, dev mode): Before: ``` real 0m31.809s user 1m3.048s sys 0m21.812s ``` After: ``` real 0m34.523s user 1m10.307s sys 0m27.223s ``` The incremental differences in time can be found in the commit messages. Fixes SCYLLADB-429 Backport: not needed. This is an enhancement to an experimental feature. Closes scylladb/scylladb#28526 * github.com:scylladb/scylladb: service: strong_consistency: Abort state_machine::apply when aborting server service: strong_consistency: Abort ongoing operations when shutting down service: client_state: Extend with abort_source service: strong_consistency: Handle abort when removing Raft group service: strong_consistency: Abort Raft operations on timeout service: strong_consistency: Use timeout when mutating service: strong_consistency: Fix indentation service: strong_consistency: Enclose coordinator methods with try-catch service: strong_consistency: Crash at unexpected exception test: cluster: Extract default config & cmdline in test_strong_consistency.py