Riemann is a network event stream processor. It is designed for monitoring, analytics, and alerts for events from multiple services. Riemann listens on port 5555 for protocol buffer messages containing events and processes them through various streams.

You can use Riemann to graph the average rate of requests in your application, email responsible parties every time an exception is thrown, and plot the 50th, 95th, and 99th percentile latencies for your HTTP service. It is a tool to make writing comprehensive, site-specific analytics easy.

Main Riemann Site

I built Riemann with the goal of getting it out the door as quickly as possible. There are many slow or kludgy parts, but they should all be readily replaceable as I find the time. Top on my list:

• Use Korma/HSQL to implement a faster index for query-heavy installations.
• Reservoir sampling
• Event pubsub