Ramen Documentation
Open source, fast, non-distributed stream processing for monitoring.
Thanks to such large companies as Google, Facebook, Linkedin and Netflix, the culture and practice of modern infrastructure monitoring has vastly improved and many good and free tools have been released publicly. Those tools understandably focus on large distributed infrastructure.
Ramen is designed for the scale most mortals are dealing with.
Ramen has been designed to process network monitoring data in embedded appliances but can be useful in other contexts. If you need an all-purpose stream processor to turn inputs time series into dashboards or alerts but do not want to deploy Kubernetes in your three racks of hardware or have only a couple of GiB left of RAM for monitoring, then you might want to consider using Ramen.
The key design principles are:
This is how it looks like:
DEFINE memory_alert AS SELECT time, host, free + used + cached AS total FROM memory GROUP BY host NOTIFY "Low RAM" WHEN free / total < 0.5;