[BUG] Failing integ test HybridQueryExplainIT.testSpecificQueryTypes_whenMultiMatchAndKnn_thenSuccessful

[martin-gaievski]

What is the bug?

One of the integ test for hybrid query explain feature is failing in CI for 2.x branch with following error in the log, see example of test suite run

REPRODUCE WITH: ./gradlew ':integTest' --tests "org.opensearch.neuralsearch.query.HybridQueryExplainIT.testSpecificQueryTypes_whenMultiMatchAndKnn_thenSuccessful" -Dtests.seed=301F3E82F0F139D6 -Dtests.security.manager=false -Dtests.locale=ar-JO -Dtests.timezone=Canada/Newfoundland -Druntime.java=21





Suite: Test class org.opensearch.neuralsearch.query.HybridQueryExplainIT

  2> REPRODUCE WITH: ./gradlew ':integTest' --tests "org.opensearch.neuralsearch.query.HybridQueryExplainIT.testSpecificQueryTypes_whenMultiMatchAndKnn_thenSuccessful" -Dtests.seed=301F3E82F0F139D6 -Dtests.security.manager=false -Dtests.locale=ar-JO -Dtests.timezone=Canada/Newfoundland -Druntime.java=21

  2> org.opensearch.client.ResponseException: method [GET], host [https://localhost:9200/], URI [/test-hybrid-large-docs-index/_search?timeout=1000s&explain=true&size=2000&search_pipeline=normalization-search-pipeline], status line [HTTP/1.1 500 Internal Server Error]

    {"error":{"root_cause":[{"type":"index_out_of_bounds_exception","reason":"Index 1 out of bounds for length 1"}],"type":"index_out_of_bounds_exception","reason":"Index 1 out of bounds for length 1"},"status":500}

        at __randomizedtesting.SeedInfo.seed([301F3E82F0F139D6:C8CEFF34FF4B90BB]:0)

        at app//org.opensearch.client.RestClient.convertResponse(RestClient.java:479)

        at app//org.opensearch.client.RestClient.performRequest(RestClient.java:371)

        at app//org.opensearch.client.RestClient.performRequest(RestClient.java:346)

        at app//org.opensearch.neuralsearch.BaseNeuralSearchIT.search(BaseNeuralSearchIT.java:605)

        at app//org.opensearch.neuralsearch.BaseNeuralSearchIT.search(BaseNeuralSearchIT.java:538)

        at app//org.opensearch.neuralsearch.BaseNeuralSearchIT.search(BaseNeuralSearchIT.java:526)

        at app//org.opensearch.neuralsearch.query.HybridQueryExplainIT.testSpecificQueryTypes_whenMultiMatchAndKnn_thenSuccessful(HybridQueryExplainIT.java:542)

  2> NOTE: leaving temporary files on disk at: /tmp/tmpawarhkcu/neural-search/build/testrun/integTest/temp/org.opensearch.neuralsearch.query.HybridQueryExplainIT_301F3E82F0F139D6-001

  2> NOTE: test params are: codec=Asserting(Lucene912): {}, docValues:{}, maxPointsInLeafNode=1591, maxMBSortInHeap=7.172532111254674, sim=Asserting(RandomSimilarity(queryNorm=true): {}), locale=ar-JO, timezone=Canada/Newfoundland

  2> NOTE: Linux 6.1.109-118.189.amzn2023.aarch64 aarch64/Eclipse Adoptium 21.0.1 (64-bit)/cpus=4,threads=7,free=316002936,total=536870912

  2> NOTE: All tests run in this JVM: [NeuralSearchIT, ValidateDependentPluginInstallationIT, HybridQueryExecutorIT, NeuralQueryEnricherProcessorIT, NeuralSparseTwoPhaseProcessorIT, NormalizationProcessorIT, RRFProcessorIT, ScoreCombinationIT, ScoreNormalizationIT, SparseEncodingProcessIT, TextChunkingProcessorIT, TextEmbeddingProcessorIT, TextImageEmbeddingProcessorIT, ByFieldRerankProcessorIT, MLOpenSearchRerankProcessorIT, HybridQueryAggregationsIT, HybridQueryExplainIT]



123 tests completed, 1 failed

How can one reproduce the bug?

I was able to repro with following command on linux system with JDK 21:

./gradlew ':integTest' --tests "org.opensearch.neuralsearch.query.HybridQueryExplainIT.testSpecificQueryTypes_whenMultiMatchAndKnn_thenSuccessful" -Dtests.seed=301F3E82F0F139D6