Yup, it's tiny and simple. But the goals are wildly different.
The same Prometheus binary you can run on a Pi scales to millions of series and millions of samples per second.
The Prometheus TSDB itself is only one part of a the larger system. But, compared to librrd, it's vastly more functional.
Besides the scaling I mentioned
* It's ACID compliant.
* It has WAL for reliability.
* It has CPU and memory efficient compression.
* It has an efficient mmap-based data loader.
RRDtool, while efficient from a '90s perspective, is a toy by comparison. And yes, I've used rrdtool. Back in old-school days when Cacti was the new hot shit compared to MRTG.
The same Prometheus binary you can run on a Pi scales to millions of series and millions of samples per second.
The Prometheus TSDB itself is only one part of a the larger system. But, compared to librrd, it's vastly more functional.
Besides the scaling I mentioned
* It's ACID compliant.
* It has WAL for reliability.
* It has CPU and memory efficient compression.
* It has an efficient mmap-based data loader.
RRDtool, while efficient from a '90s perspective, is a toy by comparison. And yes, I've used rrdtool. Back in old-school days when Cacti was the new hot shit compared to MRTG.