[BUG] p2c inflight counter leaks on downstream cancellation (no doOnCancel/doFinally)

[Aias00]

• severity: Medium
• files: shenyu-plugin/shenyu-plugin-proxy/shenyu-plugin-divide/src/main/java/org/apache/shenyu/plugin/divide/DividePlugin.java:133-135
• description: For loadBalance=p2c, responseTrigger (which calls upstream.getInflight().decrementAndGet()) is wired only via .doOnSuccess(...).doOnError(...). There is no .doOnCancel(...)/.doFinally(...). When the downstream subscriber cancels before terminal signal (client disconnect, timeout cancellation), neither onSuccess nor onError fires, so the decrement never runs. inflight ratchets upward forever.
• impact: Persistent inflight inflation on client disconnects; affected upstream is increasingly starved by p2c.
• suggested_fix: Replace .doOnSuccess(...).doOnError(...) with .doFinally(sig -> ...) (or add .doOnCancel(...)).
• confidence: Medium
• related_existing: none — [BUG] DividePlugin.beginTime is a shared mutable instance field, racy under shortestResponse load balancing #6544/FUNC-D2 is the beginTime race, not the p2c inflight leak.

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Identified during the 2026-08-02 deep re-scan; full list in docs/scan2-2026-08-02/06-medium-tiers.md.

[github-actions]

👋 Hello @yuluo-yx

A new issue has been opened by @Aias00:

• Title: [BUG] p2c inflight counter leaks on downstream cancellation (no doOnCancel/doFinally)
• Link: [BUG] p2c inflight counter leaks on downstream cancellation (no doOnCancel/doFinally) #6733

Please review when you have time. Thank you! 🙏