This feels familiar... what is Metric Store's API based on?
It is built on InfluxDB and Golang, much like Log Store.
Ingress is similar to Log Store's ingress and conforms to the Loggregator Firehose API.
Egress is a subset of the Prometheus API--might want to get used to these docs, as you'll probably be here a lot.
What are the similarities and differences between Log Store and Metric Store?
The two share some code, and originally were based on much the same code base. They are still similar on the ingress side, but more different on the egress side (see above).
Is this open source or closed source?
Open source
Where can I go to learn more about Prometheus / PromQL?
Support is only expected for the TAS side of the product. There is also an open-source version of Metric Store, but that is supported (or not) by the community.
Why did we create our own Prometheus-compatible metric store instead of relying on Prometheus itself?
In short, to unite the observability component teams around a common system because they had all diverged and found different infrastructure to meet their specific needs. Also, Metric Store was intended to solve the problems of security and scalability, providing mTLS & UAA authentication and Highly Available multi-node deployment.
What certificate does Metric Store use for its CA?