Introducing Riemann

Have you been finding yourself lately coding complex logic for deciding when to send an alert? If yes riemann is for you. You can define cewl DSLs for CEP logic for when to send an alert (or whatever else). Embeeding riemann with an example:

Including riemann in your maven dependencies.

<dependency>
    <groupId>riemann</groupId>
    <artifactId>riemann</artifactId>
    <version>0.2.6</version>
</dependency>

place riemann.conf in project root folder.

example riemann.conf

; -*- mode: clojure; -*-
; vim: filetype=clojure

(logging/init {:file "riemann.log"})

; Listen on the local interface over TCP (5555), UDP (5555), and websockets
; (5556)
(let [host "127.0.0.1"]
  (tcp-server {:host host})
  (udp-server {:host host})
  (ws-server  {:host host}))

; Expire old events from the index every 5 seconds.
(periodically-expire 5)

(let [index (index)]
  ; Inbound events will be passed to these streams:
  (streams
    (default :ttl 60
      ; Index all events immediately.
      index

      ; Log expired events.
      (expired
        (fn [event] (info "expired" event))))))

In your main() method start up riemann in your process (or in your webapp)

public static void main(String[] args) throws Exception {
    riemann.bin.main(new String[]{"riemann.config"});
}

Sending example event to this local riemann

RiemannClient c = RiemannClient.tcp("localhost", 5555);
c.connect();
c.event().
        service("fridge").
        state("running").
        metric(new Random().nextDouble()).
        tags("appliance", "cold").
        send();

c.query("tagged \"cold\" and metric > 0"); // => List<Event>;
c.disconnect();

Lets view some results - Install a local riemann dash

I don’t want to clutter my local environment with it so i’ll just use docker to install riemann-dash

sudo docker run -p 4567:4567 davidkelley/riemann-dash

Unable to find image 'davidkelley/riemann-dash' locally
Pulling repository davidkelley/riemann-dash
7911459329f4: Download complete 
b2cec74ebcfd: Download complete 
b56feebb5913: Download complete 
== Sinatra/1.4.5 has taken the stage on 4567 for development with backup from Thin

Then navigate to: http://localhost:4567/ next this is a little tricky. You will see a big Riemann word on your screen. Click it. Then click e this will edit it. Choose Gauge in the textbox type true this means your query filter is for everything. Next use the client to send some more data you will see this metric changes online realtime with your data!

source code available at: github source code