[CI] DateHistogramAggregatorTests.testAsSubAgg failing

[mark-vieira]

Build scan:
Master: https://gradle-enterprise.elastic.co/s/jn4odc7uka7xe/tests/:server:test/org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramAggregatorTests/testAsSubAgg#1
7.x: https://gradle-enterprise.elastic.co/s/p6w2gne7bvoja/tests/:server:test/org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramAggregatorTests/testAsSubAgg#1

Repro line:

./gradlew ':server:test' --tests "org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramAggregatorTests.testAsSubAgg" -Dtests.seed=998A06EB372D3C31 -Dtests.security.manager=true -Dtests.locale=es-CO -Dtests.timezone=America/Indiana/Marengo -Dcompiler.java=14 -Druntime.java=11

Reproduces locally?:
Yes, reproduced on both master and 7.x branches for me.

Applicable branches:
master and 7.x

Failure history:
https://gradle-enterprise.elastic.co/scans/tests?search.buildToolType=gradle&search.buildToolType=maven&search.relativeStartTime=P7D&search.tags=not:fips&search.tags=not:nested&search.timeZoneId=America/Los_Angeles&tests.container=org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramAggregatorTests&tests.disabledDistributions=WyJvdXRjb21lOnBhc3NlZCIsIm91dGNvbWU6c2tpcHBlZCJd&tests.sortField=FAILED&tests.test=testAsSubAgg&tests.unstableOnly=true

Failure excerpt:

org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramAggregatorTests > testAsSubAgg FAILED
    java.lang.ClassCastException: class org.apache.lucene.index.ParallelCompositeReader cannot be cast to class org.apache.lucene.index.DirectoryReader (org.apache.lucene.index.ParallelCompositeReader and org.apache.lucene.index.DirectoryReader are in unnamed module of loader 'app')
        at __randomizedtesting.SeedInfo.seed([998A06EB372D3C31:EF77AC97E69658CA]:0)
        at org.elasticsearch.search.aggregations.support.ValuesSource$Bytes$WithOrdinals$FieldData.globalOrdinalsValues(ValuesSource.java:206)
        at org.elasticsearch.search.aggregations.support.ValuesSource$Bytes$WithOrdinals.globalMaxOrd(ValuesSource.java:179)
        at org.elasticsearch.search.aggregations.bucket.terms.TermsAggregatorFactory.getMaxOrd(TermsAggregatorFactory.java:300)
        at org.elasticsearch.search.aggregations.bucket.terms.TermsAggregatorFactory.access$100(TermsAggregatorFactory.java:52)
        at org.elasticsearch.search.aggregations.bucket.terms.TermsAggregatorFactory$1.build(TermsAggregatorFactory.java:108)
        at org.elasticsearch.search.aggregations.bucket.terms.TermsAggregatorFactory.doCreateInternal(TermsAggregatorFactory.java:274)
        at org.elasticsearch.search.aggregations.support.ValuesSourceAggregatorFactory.createInternal(ValuesSourceAggregatorFactory.java:49)
        at org.elasticsearch.search.aggregations.AggregatorFactory.create(AggregatorFactory.java:250)
        at org.elasticsearch.search.aggregations.AggregatorTestCase.createAggregator(AggregatorTestCase.java:244)
        at org.elasticsearch.search.aggregations.AggregatorTestCase.createAggregator(AggregatorTestCase.java:222)
        at org.elasticsearch.search.aggregations.AggregatorTestCase.searchAndReduce(AggregatorTestCase.java:493)
        at org.elasticsearch.search.aggregations.AggregatorTestCase.searchAndReduce(AggregatorTestCase.java:441)
        at org.elasticsearch.search.aggregations.AggregatorTestCase.testCase(AggregatorTestCase.java:567)
        at org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramAggregatorTests.testAsSubAgg(DateHistogramAggregatorTests.java:225)
REPRODUCE WITH: ./gradlew ':server:test' --tests "org.elasticsearch.search.aggregations.bucket.histogram.DateHistogramAggregatorTests.testAsSubAgg" -Dtests.seed=998A06EB372D3C31 -Dtests.security.manager=true -Dtests.locale=es-CO -Dtests.timezone=America/Indiana/Marengo -Dcompiler.java=14 -Druntime.java=11

[elasticmachine]

Pinging @elastic/es-analytics-geo (:Analytics/Aggregations)

[mark-vieira]

I've muted this test in both master and 7.x since it's reproducing.

[nik9000]

I saw this this weekend while I was playing with something only vaguely related. I'll push a fix.

[polyfractal]

These generally occur because we're calling Lucene's newSearcher() instead of our own AggregatorTestCase#newIndexSearcher(). Not sure what changed to make it start failing but that's almost certainly the cause.

I don't know enough to know if we should blacklist that method from Lucene, but it'd be nice if we could...

[nik9000]

huh! It looks like AggregatorTestCase#testCase was using newSearcher. I'll swap it out.

[nik9000]

I pushed 60f91d8 with the fix @polyfractal talked about.