Engine Health Tab

Monitor engine resource usage during load tests. Track CPU and memory usage, quickly spot unhealthy engines, and fine-tune your test setup for reliable results.

The Engine Health tab shows how each engine behaves throughout the test. High resource usage on any engine can skew results, cause sampling delays, or introduce bottlenecks unrelated to your application. This tab helps you identify these issues early.
On this tab, you can:

• View the count of unhealthy engines at the top of the page: Engines that cross 80% CPU or memory usage at any point during the test are flagged as Unhealthy.
• Expand any engine panel to inspect details: You see the engine identifier (for example, engine-95815), the region (for example, us-east-1), and the number of VUs executed on that engine (for example, 10 VUs).
• Review the CPU and memory usage chart over time: The time-series chart plots virtual users (actual load), CPU usage (%), and memory usage (%) against time, with a dashed red threshold line (set at 80%) to highlight when usage exceeds limits.

Common Causes of High Engine Usage

• Scripts that perform heavy computation or contain infinite/tight loops
• High number of timeouts, exceptions, or unhandled errors
• Lack of pacing (add sleep to model realistic user behavior)
• Large response payloads causing high memory consumption and garbage collection
• Reading or processing large files from disk

If engines continue to hit high usage after addressing the above, reach out to us.