[Feature] metrics support

[CUHKSZzxy]

Objective

Align with vLLM v1 metrics system and beyond. We also refer to SGLang monitoring.

TODO

• [x] Change time.perf_counter()
• [ ] Abstract output processing outside of async engine generate()
• [ ] Expert information collections
• [ ] Grafana visualization

Usage

Start the server with --enable-metrics

lmdeploy serve api_server models--Qwen--Qwen2.5-7B-Instruct --enable-metrics

• Metrics Publishing - Logging Information will be printed on the terminal every 10 seconds

• Metrics Publishing - Prometheus & Grafana (WIP) Open http://xxxx:23333/metrics/ to view Prometheus details.

Related Issues & PR

Issue 2638, Issue 2673, PR1423