[CASSANDRA-19428] Clean up KeyRangeIterator classes

• Type: Improvement
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 5.0-rc1, 5.0, 5.1
• Component/s: Feature/2i Index
• Epic Link: Storage Attached Indexes (Phase 3)
• Change Category: Operability
• Complexity: Normal
• Platform: All

Source Control Link

https://github.com/apache/cassandra/commit/b0150e86fbf5863fd831cfca8118f1a8bd254a43. https://github.com/apache/cassandra/commit/a1b0a310eded202d86d6fd0f746a5176ff8cabbe

Test and Documentation Plan

5.0 patch PR - https://github.com/apache/cassandra/pull/3194

-Fully green CI -- [-https://app.circleci.com/pipelines/github/ekaterinadimitrova2/cassandra?branch=19428-5.0-3-]

Latest branches:

https://github.com/ekaterinadimitrova2/cassandra/tree/19428-5.0-5

https://github.com/ekaterinadimitrova2/cassandra/pull/new/19428-trunk-2

I tested locally the patch on top of the trunk - running the new fuzz tests added, and they all passed, too.

I can propagate and run full CI when we confirm the final patch.  
Clean up KeyRangeIterator classes

• replace KeyRangeConcatIterator's PriorityQeueu with List
• remove KeyRangeIterator.current and simplify
• remove injected exception and tests - not relevant to the current implementation
• expand randomized testing
• inline getCurrent() -> peek(); rename getCount to getMaxKeys
• redefine skipTo contract to not return a value (which saves unnecessary work when skipTo is called multiple times in a row)
• calling hasNext in skipTo is a pessimization; if the iterator is in DONE state, then skipTo will see it and avoid further effort; if it is not, then we are computing a next value that we're just going to throw away
• Fix a bug in QueryController#getIndexResults error handling

• Assignee: Ekaterina Dimitrova
• Reporter: Ekaterina Dimitrova

Authors

Caleb Rackliffe, Ekaterina Dimitrova, Jonathan Ellis, Michael Marshall, Piotr Kolaczkowski

Reviewers

Caleb Rackliffe, Ekaterina Dimitrova

• Created: 23/Feb/24 22:04
• Updated: 15/May/24 20:34
• Resolved: 03/Apr/24 23:08

Description

Remove KeyRangeIterator.current and simplify

Issue Links

• contains: CASSANDRA-18165 Investigate removing PriorityQueue usage from KeyRangeConcatIterator
• incorporates: CASSANDRA-18165 Investigate removing PriorityQueue usage from KeyRangeConcatIterator
• Testing discovered: CASSANDRA-19522 Test Failure: test_simple_decommission
• Testing discovered: CASSANDRA-19523 Test Failure: testMixedVersionBlockDecom
• Testing discovered: CASSANDRA-19524 Test Failure: testIncompleteState
• Testing discovered: CASSANDRA-19539 Test Failure: test_bootstrap_with_reset_bootstrap_state
• Testing discovered: CASSANDRA-19540 Test Failure: test_sstablelevelreset
• Testing discovered: CASSANDRA-19541 Test Failure: test_sstableofflinerelevel
• Testing discovered: CASSANDRA-19542 Test Failure: test_resumable_decommission
• Testing discovered: CASSANDRA-19543 Test Failure: testConcurrentReadWriteWorkload
• Testing discovered: CASSANDRA-19538 Test Failure: test_assassinate_valid_node
• links to: GitHub Pull Request #3194