Instrumentation with AspectJ

The Java Servlet Container Example contains a some basic introduction to using AspectJ probes.

AspectJ Configuration

The easiest way to configure AspectJ with Kieker is by weaving the AspectJ probes into the SuT. This requires three steps: Getting the latest Kieker AspectJ release, configuring the AspectJ weaving, and adding Kieker to the SuT start.

Downloading Kieker AspectJ Agent

To download the agent, execute wget https://repo1.maven.org/maven2/net/kieker-monitoring/kieker/2.0.4-SNAPSHOT/kieker-2.0.4-SNAPSHOT-aspectj.jar

Configuring the AspectJ weaving

The AspectJ weaving is by default configured using an aop.xml file. AspectJ has a huge syntax for weaving; it is possible to specify classes and packages for inclusion and for exclusion. It is not possible to specify weaving at method level. Assuming that you want to trace the package my.application , but exclude my.application.subpackage, the following aop.xml can be used:

<!DOCTYPE aspectj PUBLIC "-//AspectJ//DTD//EN" "http://www.aspectj.org/dtd/aspectj_1_5_0.dtd">

<aspectj>
    <weaver options="">
        <include within="my.application..*"/>
        <exclude within="my.application.subpackage.*"/>
    </weaver>

    <aspects>
      <aspect name="kieker.monitoring.probe.aspectj.operationExecution.OperationExecutionAspectAnnotation"/>
    </aspects>
</aspectj>

The OperationExecutionAspectAnnotation specifies that OperationExecutionRecord should be created. A full list of all available probes can be found in https://github.com/kieker-monitoring/kieker/tree/main/monitoring/aspectj/src/kieker/monitoring/probe/aspectj

Details regarding the AspectJ instrumentation can be found in https://eclipse.dev/aspectj/doc/released/devguide/ltw-configuration.html.

Adding Kieker to the SuT Start

To add Kieker to the SuT start, the aop.xml location needs to be specified and the javaagent needs to be specified, for example using:

java -Dorg.aspectj.weaver.loadtime.configuration=file:custom-aop.xml \
     -javaagent:benchmark/kieker-2.0.4-SNAPSHOT-aspectj.jar \
     -jar sut.jar

Please note that Kieker relies on a logging backend that is compatible with log4j; if you don’t have any in your project, please download wget https://repo1.maven.org/maven2/org/slf4j/slf4j-simple/2.0.9/slf4j-simple-2.0.9.jar and change the start like follows:

java -Dorg.aspectj.weaver.loadtime.configuration=file:custom-aop.xml \
     -javaagent:benchmark/kieker-2.0.4-SNAPSHOT-aspectj.jar \
     -cp sut.jar:slf4j-simple-2.0.9.jar
     my.application.Main

References

• AspectJ probes