Metrics
Metrics give you visibility into your app’s request traffic and resource usage so you can spot regressions, debug performance issues, and confirm a deployment is healthy.
View Metrics
Section titled “View Metrics”- Navigate to your app in the dashboard.
- Select Metrics from the sidebar.
Metrics are scoped per app. Data starts appearing after your app’s first deployment, and request data appears after the first request reaches the app.
Available Metrics
Section titled “Available Metrics”Requests
Section titled “Requests”The requests chart shows HTTP traffic to your application as a stacked bar chart, broken down by status code category:
- 2XX (green): Successful responses
- 4XX (orange): Client errors (bad requests, not found, etc.)
- 5XX (red): Server errors
Use this to spot traffic spikes, elevated error rates, or unexpected patterns.
CPU usage in vCPU units, with a line indicating your app’s CPU limit. A warning is shown if usage exceeds the limit.
Memory
Section titled “Memory”Memory usage in bytes, with a line indicating your app’s memory limit. A warning is shown if usage exceeds the limit.
| Resource | Default Limit |
|---|---|
| CPU | 0.5 vCPU |
| Memory | 500 MB |
- If your application consistently approaches the CPU limit, it may experience throttling. Consider optimizing CPU-intensive operations or reducing the work done per request.
- If your application exceeds the memory limit, it will be terminated (OOM killed) and restarted. If you see memory usage climbing toward the limit, check for memory leaks.
Replicas
Section titled “Replicas”The Metrics page shows how many replicas of your application are currently running (for example, “3/3 replicas running”). FastAPI Cloud automatically scales the number of replicas based on traffic.
If you see fewer replicas running than expected (for example, “1/2 replicas running”), it usually means a new deployment is rolling out, a replica is scaling up, or a pod crashed and is being replaced. This is typically temporary and resolves on its own. If the issue persists, check your application logs for crash errors or out-of-memory issues.
Time Ranges
Section titled “Time Ranges”Use the time range picker to control the window of data displayed across all charts. Available time ranges are 1 hour, 6 hours, and 1 day.
Chart Controls
Section titled “Chart Controls”- Crosshair sync. To enable crosshair sync, search for the settings button in the top right corner of the Metrics page and toggle the option. When enabled, hovering on one chart highlights the same timestamp across all charts on the page.