analyze_async_bottlenecks
Identify wasteful async machinery in V8 CPU profiles, such as microtask queues and nextTick saturation, to determine if event-loop overhead is the real bottleneck.
Instructions
Detects event-loop overhead in a V8 CPU profile by identifying V8 internal frames that represent async machinery — microtask queue processing, nextTick saturation, and timer/immediate callbacks. These frames are invisible to most profilers but consume real CPU when promise chains are deep or nextTick is overused. Use to answer: is the bottleneck async orchestration overhead rather than synchronous computation?
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| profile_path | Yes | Absolute path to the .cpuprofile file | |
| threshold_percent | No | Async overhead percentage above which a warning is emitted in the verdict (default: 10) |