We present riemann: a low-latency transient shared state stream processor.
This opensource monitoring tool is written by Kyle Kingsbury and
maintained by the community. Its unique design makes it as flexible as
it gets by melting the walls between configuration and code. Whenever its rich API
doesn't fit the use-case, it's as simple as using any library in the clojure or java
ecosystem and importing it into the configuration.
We present riemannn's basic concepts, as well as some key elements of its API.
Moreover, we illustrate its usefulness in our Tier-1 by showing a few examples of use-cases at CC-IN2P3.
For instance, its ability to aggregate thousands of metrics along high-level metadata keys using straightforward
configuration entries is illustrated. Its integration with other monitoring tools like Nagios, InfluxDB, Elasticsearch, etc. is presented.