pedro-carneiro / managed-utils

Utility classes for exposing attributes

Managed utilities

This project holds some utility classes that expose bean properties as JMX attributes. First and foremost, it holds classes that expose the queue sizes of some common thread pool implementations, since I was unable to find this done anywhere else.

Install

Import the dependency into your project.

On maven, use:

<dependency>
  <groupId>com.pcarneiro.utilities</groupId>
  <artifactId>managed-utils</artifactId>
  <version>${managed-utils.version}</version>
</dependency>

Several other dependency managers are supported. Please check the Maven Central repository page for further details.

Usage

Wrap your thread pool implementation with one of the provided classes.

Example (for Spring based XML configuration):

<bean id="my.managed.executor" class="com.pcarneiro.utilities.managed.ManagedThreadPoolExecutor"
      c:executor-ref="my.executor"/>

Similarly, you can also wrap your Guava Cache to expose statistics:

<bean id="my.managed.cache" class="com.pcarneiro.utilities.managed.ManagedCache"
      c:cache-ref="my.cache"/>

Then, expose the bean through JMX:

<bean id="exporter" class="org.springframework.jmx.export.MBeanExporter">
  <property name="beans">
    <map>
      <entry key="bean:name=myManagedExecutor" value-ref="my.managed.executor"/>
      <entry key="bean:name=myManagedCache" value-ref="my.managed.cache"/>
    </map>
  </property>
</bean>

Motivation

Thread pools are a relevant tool, when it comes to unleashing the potential of the JVM concurrency capabilities. When used along with a task queue, they can even be effectively used as rate limiters.

As such, it's important to monitor these queues, to evaluate how to dimension your thread pool, and to better understand how it behaves under load.

Should you collect your metrics from managed beans, then this project may be useful to you.