[CI] ThreadPoolMergeExecutorServiceDiskSpaceTests testEnqueuedMergeTasksAreUnblockedWhenEstimatedMergeSizeChanges failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic #9335 / single-processor-node-tests
• elasticsearch-pull-request #79990 / part-1

Reproduction Line:

./gradlew ":server:test" --tests "org.elasticsearch.index.engine.ThreadPoolMergeExecutorServiceDiskSpaceTests.testEnqueuedMergeTasksAreUnblockedWhenEstimatedMergeSizeChanges" -Dtests.seed=87831EAA8057F1EE -Dtests.configure_test_clusters_with_one_processor=true -Dtests.locale=syr -Dtests.timezone=Europe/Bratislava -Druntime.java=24

Applicable branches:
main

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.util.ConcurrentModificationException: null

Issue Reasons:

• [main] 2 failures in test testEnqueuedMergeTasksAreUnblockedWhenEstimatedMergeSizeChanges (0.4% fail rate in 479 executions)

Note:
This issue was created using new test triage automation. Please report issues or feedback to es-delivery.

[elasticsearchmachine]

This has been muted on branch main

Mute Reasons:

• [main] 2 failures in test testEnqueuedMergeTasksAreUnblockedWhenEstimatedMergeSizeChanges (0.4% fail rate in 479 executions)

Build Scans:

• elasticsearch-periodic #9335 / single-processor-node-tests
• elasticsearch-pull-request #79990 / part-1

[elasticsearchmachine]

Pinging @elastic/es-distributed-indexing (Team:Distributed Indexing)