Aias00 opened a new issue, #6610: URL: https://github.com/apache/shenyu/issues/6610
- Severity: Critical - Location: `shenyu-common/src/main/java/org/apache/shenyu/common/concurrent/DiscardOldestPolicy.java:28-31`; `shenyu-common/src/main/java/org/apache/shenyu/common/concurrent/MemorySafeLinkedBlockingQueue.java:107-113` - Description: `DiscardOldestPolicy.reject(e, queue)` does `queue.poll(); queue.offer(e);`. The `queue` is the `MemorySafeLinkedBlockingQueue` itself (passed as `this`). `queue.offer(e)` dispatches to the overridden `offer`, which re-checks `hasRemainedMemory()`. `Runtime.freeMemory()` does not change in the microsecond window (`maxAvailable` refreshed only every 50ms by `MemoryLimitCalculator`), so the check is still false → `rejector.reject(e, this)` re-enters `DiscardOldestPolicy.reject`. The queue shrinks via `poll()`; once empty `poll()` returns null but `offer(e)` still recurses forever. Result: `StackOverflowError` instead of "discard oldest" — happening precisely in the low-memory condition the queue exists to handle. The `Rejector` interface documents `DiscardOldestPolicy` as a supported implementation. - Impact: Any deployment wiring `queue.setRejector(new DiscardOldestPolicy<>())` crashes the offering thread (often a netty/transport worker) the first time free memory drops below `maxFreeMemory`. - Suggested fix: Add a bypass method (e.g. `offerIgnoringMemory`) that calls `super.offer(e)`; have `DiscardOldestPolicy.reject` use it. Or guard `reject` to not re-invoke the memory-checked `offer`. - Confidence: High - Related existing: none — #6445 was `put` rejecting *after* enqueue (different method, fixed); this is unconditional recursion in `offer` via the discard-oldest rejector. --- _Identified during the 2026-08-02 deep re-scan; full list in [`docs/scan2-2026-08-02/00-consolidated-critical-high.md`](docs/scan2-2026-08-02/00-consolidated-critical-high.md)._ -- 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]
