kete1987 opened a new pull request, #56234: URL: https://github.com/apache/spark/pull/56234
### What changes were proposed in this pull request? In unbounded memory mode (the default, `boundedMemoryUsage = false`), `RocksDBMemoryManager` creates a new `LRUCache` per instance: https://github.com/apache/spark/blob/d7df1920cfb8577c17a9b1555592d3772f061417/sql/core/src/main/scala/org/apache/spark/sql/execution/streaming/state/RocksDBMemoryManager.scala#L161 but `RocksDB.close()` never calls `lruCache.close()`: https://github.com/apache/spark/blob/d7df1920cfb8577c17a9b1555592d3772f061417/sql/core/src/main/scala/org/apache/spark/sql/execution/streaming/state/RocksDB.scala#L2614-L2627 The Java `LRUCache` wrapper holds a C++ `shared_ptr<Cache>`, so the native object is only freed when the JVM GC finalizes the wrapper — which rarely happens under low heap pressure. This causes native memory to accumulate until GC eventually runs, leading to OOM kills in long-running processes or CI runs with many RocksDB-heavy test suites. The fix adds an explicit `lruCache.close()` call in `RocksDB.close()` for unbounded mode. In bounded mode the cache is a shared singleton managed by `RocksDBMemoryManager` and must not be closed per instance. This is a separate issue from SPARK-56523 (Statistics native memory leak), which was already fixed. ### Why are the changes needed? Without explicit `close()`, each `RocksDB` instance in unbounded mode leaks one `LRUCache` worth of native memory (`blockCacheSizeMB`, default 8 MB) for as long as GC does not run. The memory is never reclaimed deterministically. A standalone reproducer tool confirms ~8.5 MB of native memory growth per open/close cycle in leak mode vs flat memory in fixed mode: https://github.com/kete1987/rocksdb-leak-tool ### Does this PR introduce _any_ user-facing change? No. ### How was this patch tested? Added a test in `RocksDBSuite` (`SPARK-57183: LRUCache is closed on RocksDB.close() in unbounded memory mode`) that verifies the native handle is released after `close()` via `LRUCache.isOwningHandle()`. I affirm that the contribution is my original work and that I license the work to the project under the project's open source license. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
