[CI] ClassificationIT testSetUpgradeMode_ExistingTaskGetsUnassigned failing

[elasticsearchmachine]

Build Scans:

• elasticsearch-periodic #6430 / openjdk17_checkpart4_java-matrix
• elasticsearch-intake #18147 / part4

Reproduction Line:

./gradlew ":x-pack:plugin:ml:qa:native-multi-node-tests:javaRestTest" --tests "org.elasticsearch.xpack.ml.integration.ClassificationIT.testWithOnlyTrainingRowsAndTrainingPercentIsFifty_DependentVariableIsKeyword" -Dtests.seed=B02FCEFFF62270B0 -Dtests.locale=or-Orya-IN -Dtests.timezone=Canada/Saskatchewan -Druntime.java=17

Applicable branches:
8.17

Reproduces locally?:
N/A

Failure History:
See dashboard

Failure Message:

java.lang.AssertionError: Stats were: {"id":"classification_training_percent_is_50_keyword","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":100},{"phase":"fine_tuning_parameters","progress_percent":59},{"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":1739657833678,"peak_usage_bytes":58080,"status":"ok"},"analysis_stats":{"classification_stats":{"timestamp":1739657833678,"iteration":10,"hyperparameters":{"class_assignment_objective":"maximize_minimum_recall","alpha":3.1453819005602686,"downsample_factor":0.3685444750839404,"eta":0.7182545337363935,"eta_growth_rate_per_tree":1.1554419751368594,"feature_bag_
[truncated]

Issue Reasons:

• [8.17] 2 failures in test testSetUpgradeMode_ExistingTaskGetsUnassigned (2.0% fail rate in 101 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 8.17

Mute Reasons:

• [8.17] 2 failures in test testSetUpgradeMode_ExistingTaskGetsUnassigned (2.0% fail rate in 101 executions)

Build Scans:

• elasticsearch-periodic #6430 / openjdk17_checkpart4_java-matrix
• elasticsearch-intake #18147 / part4

[elasticsearchmachine]

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

[valeriy42]

Closed in #125510