[CI] ClassificationIT testWithOnlyTrainingRowsAndTrainingPercentIsFifty_DependentVariableIsBoolean failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-intake #17232 / part4
• elasticsearch-intake #16911 / part4

Reproduction Line:

./gradlew ":x-pack:plugin:ml:qa:native-multi-node-tests:javaRestTest" --tests "org.elasticsearch.xpack.ml.integration.ClassificationIT.testWithOnlyTrainingRowsAndTrainingPercentIsFifty_DependentVariableIsBoolean" -Dtests.seed=A8A2B77E11BFEDDA -Dtests.locale=en-001 -Dtests.timezone=America/North_Dakota/New_Salem -Druntime.java=23

Applicable branches:
8.18

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.lang.AssertionError: Stats were: {"id":"classification_training_percent_is_50_boolean","state":"started","progress":[{"phase":"reindexing","progress_percent":100},{"phase":"loading_data","progress_percent":100},{"phase":"feature_selection","progress_percent":100},{"phase":"coarse_parameter_search","progress_percent":86},{"phase":"fine_tuning_parameters","progress_percent":0},{"phase":"final_training","progress_percent":0},{"phase":"writing_results","progress_percent":0},{"phase":"inference","progress_percent":0}],"data_counts":{"training_docs_count":150,"test_docs_count":0,"skipped_docs_count":0},"memory_usage":{"timestamp":1738683705089,"peak_usage_bytes":19305,"status":"ok"},"node":{"id":"I5OExxU4RnG37JuzZYAC8g","name":"javaRestTest-1","ephemeral_id":"our5btA8RraANvKvTR8B4g","transport_address":"127.0.0.1:35695","attributes":{"ml.config_version":"12.0.0","ml.allocated_processors":"32","ml.max_jvm_size":"536870912","transform.config_version":"10.0.0","xpack.installed":"true","tes
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Issue Reasons:

• [8.18] 2 failures in test testWithOnlyTrainingRowsAndTrainingPercentIsFifty_DependentVariableIsBoolean (0.5% fail rate in 390 executions)
• [8.18] 2 failures in step part4 (4.4% fail rate in 45 executions)
• [8.18] 2 failures in pipeline elasticsearch-intake (4.4% fail rate in 45 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 8.18

Mute Reasons:

• [8.18] 2 failures in test testWithOnlyTrainingRowsAndTrainingPercentIsFifty_DependentVariableIsBoolean (0.5% fail rate in 390 executions)
• [8.18] 2 failures in step part4 (4.4% fail rate in 45 executions)
• [8.18] 2 failures in pipeline elasticsearch-intake (4.4% fail rate in 45 executions)

Build Scans:

• elasticsearch-intake #17232 / part4
• elasticsearch-intake #16911 / part4

[elasticsearchmachine]

Pinging @elastic/ml-core (Team:ML)