[CASSANDRA-18341] Accord simulator fails with "available partitions are empty!"

• Type: Bug
• Status: Open
• Priority: Normal
• Resolution: Unresolved
• Fix Version/s: 5.x
• Component/s: Accord, Test/fuzz
• Bug Category: Correctness - Test Failure
• Severity: Normal
• Complexity: Normal
• Discovered By: Unit Test
• Platform: All
• Assignee: Unassigned
• Reporter: David Capwell
• Created: 16/Mar/23 21:14
• Updated: 16/Mar/23 21:16

Description

With the change to allow accord to run with multiple partitions in simulator we can hit an edge case where all partitions are used in queries, so the current query isn’t able to find a partition to use, causing this error

junit.framework.AssertionFailedError: available partitions are empty!
	at org.apache.cassandra.simulator.paxos.AbstractPairOfSequencesPaxosSimulation.consume(AbstractPairOfSequencesPaxosSimulation.java:252)
	at org.apache.cassandra.simulator.paxos.AbstractPairOfSequencesPaxosSimulation.access$000(AbstractPairOfSequencesPaxosSimulation.java:72)
	at org.apache.cassandra.simulator.paxos.AbstractPairOfSequencesPaxosSimulation$2.get(AbstractPairOfSequencesPaxosSimulation.java:211)
	at org.apache.cassandra.simulator.paxos.AbstractPairOfSequencesPaxosSimulation$2.get(AbstractPairOfSequencesPaxosSimulation.java:207)
	at org.apache.cassandra.simulator.Actions.next(Actions.java:145)
	at org.apache.cassandra.simulator.Actions.lambda$streamNextSupplier$3(Actions.java:154)
	at org.apache.cassandra.simulator.Actions$LambdaAction.performSimple(Actions.java:63)
	at org.apache.cassandra.simulator.Action.performAndRegister(Action.java:468)
	at org.apache.cassandra.simulator.Action.perform(Action.java:486)
	at org.apache.cassandra.simulator.ActionSchedule.next(ActionSchedule.java:378)
	at org.apache.cassandra.simulator.paxos.PaxosSimulation$2.next(PaxosSimulation.java:255)
	at org.apache.cassandra.simulator.paxos.PaxosSimulation.run(PaxosSimulation.java:227)
	at org.apache.cassandra.simulator.paxos.AbstractPairOfSequencesPaxosSimulation.run(AbstractPairOfSequencesPaxosSimulation.java:295)
	at org.apache.cassandra.simulator.paxos.PairOfSequencesAccordSimulation.run(PairOfSequencesAccordSimulation.java:62)
	at org.apache.cassandra.simulator.SimulationRunner$Run.run(SimulationRunner.java:374)
	at org.apache.cassandra.simulator.paxos.AccordSimulationRunner$Run.run(AccordSimulationRunner.java:39)
	at org.apache.cassandra.simulator.paxos.AccordSimulationRunner$Run.run(AccordSimulationRunner.java:30)
	at org.apache.cassandra.simulator.SimulationRunner$BasicCommand.run(SimulationRunner.java:355)
	at org.apache.cassandra.simulator.paxos.AccordSimulationRunner.main(AccordSimulationRunner.java:76)
	at org.apache.cassandra.simulator.test.ShortAccordSimulationTest.simulationTest(ShortAccordSimulationTest.java:32)

See https://app.circleci.com/pipelines/github/dcapwell/cassandra/1947/workflows/05ee1183-36a0-41de-a798-e49b4e1ec413/jobs/19052

Issue Links

• blocks: CASSANDRA-18196 Initial Merge of Accord Feature Branch to Trunk