LongRange/DoubleRange#getQuery(fastMatchQuery, valueSource) reports its Weight as cacheable without asking the fast-match query, so after an in-place doc-values update the query cache keeps returning the old matches
Finding LFV-320Area: facet / range drill-down queries (LongRange and DoubleRange ValueSourceQuery and MultiValueSourceQuery) and the query cachePriority: lowImpact: silent wrong resultsNovelty: new
AI-assisted finding, confirmed by automated checks, not yet triaged by a human Lucene committer. This site files nothing upstream.
What it shows
You build a range filter or drill-down with LongRange or DoubleRange#getQuery(fastMatchQuery, valueSource) whose fast-match query reads a doc-values field (for example NumericDocValuesField.newSlowExactQuery("inStock", 1)), run it through a query cache, then change that field for one document in place with IndexWriter#updateNumericDocValue and reopen the reader. You expect the reopened searcher to use the new value, because a query that depends on updated doc values must report itself not cacheable (SegmentCacheable), and the fast-match query alone does. Instead the range query's Weight#isCacheable asks only the value source, the segment keeps its core cache key, and the cache keeps serving the pre-update result (5 hits instead of 4 in the repro) until the segment is merged away or the entry is evicted.
The test shows that a LongRange#getQuery(fastMatch, valueSource) query whose fast match reads doc values (inStock) keeps its query-cache entry after updateNumericDocValue changes inStock and the reader is reopened.
Expected vs actual
Expected: 0 hits (the only document is no longer in stock). Actual (-ea and -da): 1 hit, the cached pre-update result, because the range Weight's isCacheable ignores the fast-match Weight.
Files
Run it
- Tested on Lucene main e1faeba08bde (2026-11-02): still reproduces.
- Tested on Lucene main 645d4fe14a20 (2026-10-28): reproduced.
- Recorded outcome of run 1 on Lucene main 645d4fe14a20: 1 test(s) run, 1 failed.
- How to read the outcome: a failing test is the finding reproducing (the failure message states expected against actual).
- Seeds: a rerun with the same seed replays the same random choices. Assertions off (-da -dsa -Dtests.asserts=false) is the production-like setting.
# Lucene checkout at the tested commit, built with: ./gradlew --no-daemon assemble (JDK 25)
LUCENE=/path/to/lucene; V=12.0.0-SNAPSHOT
CP=$LUCENE/lucene/core/build/libs/lucene-core-$V.jar
CP=$CP:$LUCENE/lucene/codecs/build/libs/lucene-codecs-$V.jar
CP=$CP:$LUCENE/lucene/test-framework/build/libs/lucene-test-framework-$V.jar
CP=$CP:$LUCENE/lucene/facet/build/libs/lucene-facet-$V.jar
CP=$CP:randomizedtesting-runner-2.9.2.jar:junit-4.13.2.jar:hamcrest-3.0.jar # test-framework dependencies (Maven Central)
CP=$CP:junit-platform-console-standalone-6.1.3.jar # JUnit Platform console launcher (Maven Central)
javac -d classes -cp "$CP" $(find src -name '*.java')
# run 1: assertions on, seed DEADBEEF
java -ea -esa --add-modules jdk.incubator.vector --enable-native-access=ALL-UNNAMED -Dtests.seed=DEADBEEF \
-cp "classes:$CP" org.junit.platform.console.ConsoleLauncher \
execute --select-class org.apache.lucene.facet.range.TestRangeFastMatchQueryCacheThe module(s) facet also need their third-party runtime jars; ./gradlew -p lucene/<module> dependencies lists them.
Gradle alternative: copy the test into the matching module's src/test/ tree of the checkout and run ./gradlew -p lucene/<module> test --tests <class> -Ptests.seed=<seed> (add -Ptests.asserts=false for a run without assertions).
Formal models and scripts this finding's part of the hunt used: query-cache-correctness
Feedback
Open an issue in lucene-ai-bug-hunt. Please do not open issues or pull requests in apache/lucene about this finding unless a Lucene committer agrees it should be filed.
Snapshot of 2026-11-04. AI-assisted; not yet triaged by a human Lucene committer. Feedback: open an issue in lucene-ai-bug-hunt.