Comment by imiric
18 days ago
This is a common myth. Debugging unikernels is indeed possible[1][2]. It may not be the type of debugging you're already used to, but then again, unikernels are very different from containers and VMs, so some adjustment is expected.
As for observability, why is that the concern of unikernels? That's something your application should do. You're free to hook it up to any observability stack you want.
[1]: https://nanovms.com/dev/tutorials/debugging-nanos-unikernels...
Respectfully, neither of these docs strike me as really sufficient to debug live running systems in the critical path for paying users. The first seems to be related to the inner development loop and local the second is again how to attach gdb to debug something in a controlled environment
Crash reporting, telemetry, useful queuing/saturation measures or a Rosetta Stone of “we look at X today in system and app level telemetry, in the <unikernel system> world we look at Y (or don’t need X for reason Z) would be more in the spirit of parity
Systems are often somewhat “hands off” in more change control sensitive environments too, these guides presume full access, line of sight connectivity and a expert operator which are three unsafe assumptions in larger production systems IMO
You can expose Unikernel application metrics in Prometheus text exposition format at `/metrics` http page and collect them with Prometheus or any other collector, which can scrape Prometheus-compatible targets. Alternatively, you can push metrics from the Unikernel to the centralized database for metrics for further investigation. Both pull-based and push-based metrics' collection is supported by popular client libraries for metrics such as https://github.com/VictoriaMetrics/metrics .
You can emit logs by the Unikernel app and send them to a centralized database for logs via syslog protocol (or any other protocol) for further analysis. See, for example, how to set up collect ing logs via syslog protocol at VictoriaLogs - https://docs.victoriametrics.com/victorialogs/data-ingestion...
You can expose various debug endpoints via http at the Unikernel application for debugging assistance. For example, if the application is written in Go, it is recommended exposing endpoints for collecting CPU, memory and goroutines profiles from the running application.