Codahale Metrics and Spring

This is a revision of my previous post on Coda Hale Metrics available here.

Goal: Integrate Metrics (v 3.1.0) and Spring (v 4.1.x) in a JEE environment.

Metrics-spring resides here. Code snippets to help you get started below:

1. Add the following dependency in pom.xml

<dependency>
     <groupid>io.dropwizard.metrics</groupid>
     <artifactid>metrics-servlets</artifactid>
     <version>3.1.0</version>
</dependency>
<dependency>
     <groupid>com.ryantenney.metrics</groupid>
     <artifactid>metrics-spring</artifactid>
     <version>3.0.3</version>
</dependency>
..
Other metrics dependencies

2. Add the following in web.xml

<servlet>
 <servlet-name>metrics-admin</servlet-name>
 <servlet-class>com.codahale.metrics.servlets.AdminServlet</servlet-class>
</servlet>
<servlet-mapping>
 <servlet-name>metrics-admin</servlet-name>
 <url-pattern>/metrics/admin/*</url-pattern>
</servlet-mapping>

3. Define metrics.xml and include it in your main spring configuration file.

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:metrics="http://www.ryantenney.com/schema/metrics"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans.xsd
               http://www.ryantenney.com/schema/metrics
               http://www.ryantenney.com/schema/metrics/metrics-3.0.xsd">

    <!-- Registry should be defined in only one context XML file -->
    <metrics:metric-registry id="metrics" />

    <metrics:health-check-registry id="healthCheck" />

    <!-- annotation-driven must be included in all context files -->
    <metrics:annotation-driven metric-registry="metrics"
        health-check-registry="healthCheck" />

    <!-- (Optional) Registry should be defined in only one context XML file -->
    <metrics:reporter type="console" metric-registry="metrics"
        period="1m" />

    <bean
        class="org.springframework.web.context.support.ServletContextAttributeExporter">
        <property name="attributes">
            <map>
                <entry key="com.codahale.metrics.servlets.MetricsServlet.registry">
                    <ref bean="metrics" />
                </entry>
                <entry key="com.codahale.metrics.servlets.HealthCheckServlet.registry">
                    <ref bean="healthCheck" />
                </entry>
            </map>
        </property>
    </bean>
</beans>

4. Define HealthCheck classes and annotate methods with @Timed as per Metrics documentation. And we are done!

Navigate to: http://hostname:port/<webappname>/metrics/admin to view "Operational Menu"

The output metrics is dumped in JSON format. You can parse it and pass it to your favorite graphing library.

Note: All metrics are reported via Console. You can easily enable other reporters in metrics.xml.