Yeah, that's kinda a dick move. I was waiting for 1.0 before giving it another real go (after their decision to rewrite everything for 0.9). Looks like I'll be checking out something else now, maybe Prometheus[1] or DalmatinerDB[2] will fit the bill.
While Prometheus's built-in local storage is not distributed, we are in the process of implementing generic interfaces to allow Prometheus to talk to decoupled distributed, horizontally scalable, durable, remote storage (or even other non-storage systems like queues etc.). There will be several implementations sitting behind this interface in the end (see already Vulcan from DO and Frankenstein from Weaveworks, both experimental right now), depending on what you'd rather run and what fits your use case best.
Most importantly, Prometheus will never decide to exclude a feature for commercial reasons. As it's a 100% open-source and independent project not controlled by any single company, we don't have those kinds of incentives. We just want to build the best monitoring system. Note that we still say "no" to a lot of features, but that's only for technical reasons, to avoid bloat, or to keep the project maintainable.
Note: I am not affiliated with any of these services. I just have a very strong interest in nagios/icinga/riemann/graphite/grafana dying since my painful experience of setting up and maintaining them.
We're looking into Cyanite as an alternative. It speaks the various Graphite protocols and feeds data into Cassandra, which takes care of the HA concerns. I haven't built it yet but I'm fairly certain we can run it in Kubernetes to make the entire stack HA.
We dropped InfluxDB after they introduced their enterprise version.
Currently, we are running several nodes of Riemann/Cyanite/Cassandra.
It works very well, integration is pretty straight forward.
I've not yet used in in production, but I have kicked the tires enough to know that a) it's (much) faster, and b) I'm planning a production deployment this fall.
For the most part it's compatible with Cassandra out-of-the-box, i.e. many well-known frameworks that run on top of Cassandra "just work". The main thing it's missing is support for Lightweight Transactions (scheduled for the 2.0 release).
The dev team behind ScyllaDB is rock solid, very competent.
1. https://prometheus.io/ 2. https://dalmatiner.io/