Go 1.25 flight recorder buffers execution traces in-memory

Summary

Latency debugging in long-running services now shifts from probabilistic sampling (storage-heavy, requires fleet-wide infrastructure) to scalpel-precise snapshots triggered by your own error detection logic. You collect traces only for the problematic window, not days of data.

Why it matters

Latency debugging in long-running services now shifts from probabilistic sampling (storage-heavy, requires fleet-wide infrastructure) to scalpel-precise snapshots triggered by your own error detection logic. You collect traces only for the problematic window, not days of data.

Sources

1. 1.flight recording is now available in Go 1.25
2. 2.The flight recorder buffers the last few seconds of the trace in memory
3. 3.you can expect a few MB of trace data to be produced per second of execution, or 10 MB/s for a busy service
4. 4.MinAge configures the duration for which trace data is reliably retained
5. 5.MaxBytes configures the size of the buffered trace so you don't blow up your memory usage