dify - 💡(How to fix) Fix SSE interface hangs with only "event: ping" and fails after load testing (Redis connection error)

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Dify version

1.14.2

Cloud or Self Hosted

Self Hosted (Docker)

Steps to reproduce

Deploy Dify 1.14.2 using Docker Compose. Configure an LLM application and enable the SSE (Server-Sent Events) chat interface. Use a load testing tool (e.g., Apifox) to perform a stress test on the chat interface with concurrent users (e.g., 60 users for 5 minutes). After the test, attempt to access the chat interface normally via the web UI or API. Observe the network response and backend logs.

✔️ Expected Behavior

The system should handle high concurrency gracefully or reject requests with proper error codes. After the load test, the service should automatically recover. The chat interface should return valid text responses (e.g., event: message) instead of hanging.

❌ Actual Behavior

After load testing, all chat interfaces become unusable. The client receives continuous event: ping but no actual text content (event: message). The backend logs show Redis connection errors (e.g., Redis connection pool exhausted or Connection refused). The service does not recover until the Docker containers or Redis service are manually restarted.

error.txt