Formal models and scripts: trydvupdate-bypasses-ram-buffer-unbounded-heap

Tools: Python

These are the working models and scripts this part of the hunt used. Some encode the code as it is (a counterexample is the expected result), others a fixed or correct variant; read the header comment of each file. Paths inside them were replaced by placeholders such as $LUCENE (a Lucene checkout) and $WORK.

Findings

• IndexWriter.tryUpdateDocValue never checks the RAM buffer for the doc-values updates it adds, so they pile up on the heap without bound until the next refresh, flush() or commit (finding LFV-1075; repro · finding page)

Files

• tryupdatedocvalue-skips-reader-pool-ram-check/model/predict_mbt.py (used for LFV-1075)

How to run

• Python: python3 <file>.py; scripts that import z3 need the z3-solver package.

Snapshot of 2026-11-03. AI-assisted; not yet triaged by a human Lucene committer. Feedback: open an issue in lucene-ai-bug-hunt.