test: Add standalone reproduction for cache lock client disconnect bug #798
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This adds a self-contained reproduction tool that demonstrates a bug where Pingora doesn't detect client disconnects while waiting on a cache lock, causing servers to hold connections for the full lock timeout (up to 60s) even after clients have disconnected. The reproduction includes: - slow_origin.rs: A simple slow origin server (pure Rust, no OpenResty) - proxy.rs: Minimal Pingora proxy with caching and cache lock enabled - test_client.rs: Test client that measures disconnect detection time To run: cd cache-lock-bug-repro && ./run_test.sh Results without fix: Server takes 19-24 seconds to close after disconnect Results with fix: Server closes in ~180 microseconds after disconnect A proposed fix is available in branch skidder/cache-lock-client-disconnect-v1 Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
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Summary
This PR adds a standalone reproduction tool that demonstrates a bug where Pingora doesn't detect client disconnects while waiting on a cache lock, causing servers to hold connections for the full lock timeout (up to 60 seconds) even after clients have disconnected.
The Bug
When multiple requests hit the same uncached URL with cache lock enabled:
This causes:
The Reproduction
The
cache-lock-bug-repro/directory contains:slow_origin.rs: Pure Rust slow origin server (no OpenResty dependency)proxy.rs: Minimal Pingora proxy with caching and cache lock enabledtest_client.rs: Test client that measures server disconnect detection timeTo run:
cd cache-lock-bug-repro ./run_test.shTest Results
Proposed Fix
A proposed fix is available in a separate branch:
skidder/cache-lock-client-disconnect-v1The fix uses
tokio::select!to race the cache lock wait against client disconnect detection viasession.downstream_session.read_body_or_idle(true).Test plan
🤖 Generated with Claude Code