How to Build a Monitoring System Using Riemann | Part 1

Let’s start Riemann and Riemann-dash

1) service Riemann start  OR Riemann OR Riemann /etc/Riemann/riemann.config

You can start Riemann using any one of the above commands.

For this example, Riemann-java-client is being used and we will send our own user-defined events from this java program using the Riemann java client library.

Pom file structure:

<?xml version="1.0" encoding="UTF-8"?>  
 <project xmlns="http://maven.apache.org/POM/4.0.0"  
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
      xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">  
   <modelVersion>4.0.0</modelVersion>  
   <groupId>com.ali</groupId>  
   <artifactId>riemann</artifactId>  
   <version>1.0-SNAPSHOT</version>  
 <repositories>  
   <repository>  
     <id>clojars.org</id>  
     <url>http://clojars.org/repo</url>  
   </repository>  
 </repositories>  
   <dependencies>  
     <dependency>  
       <groupId>io.riemann</groupId>  
       <artifactId>riemann-java-client</artifactId>  
       <version>0.4.2</version>  
     </dependency>  
   </dependencies>  
 </project>

The below example is from a java class that has been copied from the riemann-java client git homepage with some modifications.

 import io.riemann.riemann.client.RiemannClient;  
   
 import java.io.IOException;  
   
   
 public class BasicEventTest {  
   public static void main(String... args) throws IOException, InterruptedException {  
     RiemannClient c = RiemannClient.tcp("localhost", 5555); // creating connection object 
     c.connect();  // connecting to riemann server
     int temperature = 1;  
     while (true) {  
       if (temperature > 10) temperature = 1;  
       Thread.sleep(1000);  
       c.event().                // creating event
           service("fridge").  
           state("running").  
           metric(temperature++).  
           tags("appliance", "cold").  
           send().              // sending event
           deref(5000, java.util.concurrent.TimeUnit.MILLISECONDS);  
     }  
   }  
 }  
   

The Process:

1. Creating Riemann client which will connect to the specified Riemann server.
2. Creating an event and giving a service name, state, metric value, tags for extra metadata; then sending it to the Riemann server.

Once this program runs, you will be able to see the event on the Riemann dashboard.

The temperature we are sending as a metric value is associated with the service name “fridge”. Once you click on the fridge service it will show more details it is associated with down below.

In this case, the value of temperature is changing every one second because we are sending a new metric value every 1 second in our java program. The TTL value here is 60. Each event will be present in Riemann for 60 seconds only.  You can configure it in Riemann.config file.

*Point to remember: this will be the main point of need for Graphite coming in part 2. 

This service and metric is a dummy.

Final Example of an Event Sent From Java Application:

 import io.riemann.riemann.client.RiemannClient;  
   
 import java.io.IOException;  
 import java.lang.management.ManagementFactory;  
 import java.lang.management.MemoryMXBean;  
   
 public class BasicEventTest {  
   public static void main(String... args) throws IOException, InterruptedException {  
     RiemannClient c = RiemannClient.tcp("localhost", 5555);  
     c.connect();  
     while (true) {  
       Thread.sleep(1500);  
       MemoryMXBean memoryMXBean = ManagementFactory.getMemoryMXBean();  
       c.event().  
           service("jvm.nonheap.memory").  
           // state("running").   state is not needed here  
           metric(memoryMXBean.getNonHeapMemoryUsage().getUsed() / 1024).  
           tags("jvm nonheap used memory").  
           send().  
           deref(5000, java.util.concurrent.TimeUnit.MILLISECONDS);  
     }  
   }  
 }  
   

In this example we are sending JVM non-heap used memory using Memory Mbean and sending its value to Riemann.

Similarly, we can send all JVM related metrics like JVM CPU, thread count, heap memory usage, and more using Mbeans.

What is Next?

Keep an eye out for part 2 where we will cover Riemann integration with Graphite and dive into why it is needed.

Check out more of our how-to articles like How to Get Started with Selenium Automation