Basics

The core of hoopoe-profiler is the java agent to instrument the code of profiled application. The jar file also contains bundled plugins and extensions.

  1. Download the hoopoe-agent.jar.

  2. Register hoopoe-agent.jar in application’s java options: -javaagent:<path-to-hoopoe-agent.jar>

For most application servers setup is done. We know some peculiarities of JBoss servers, see below if you use one.

JBoss Servers

JBoss servers (AS, EAP, WildFly) have some special traits to be concerned when using java agents:

  1. ModuleClassLoader breaks javaclassloader contract (MODULES-250).

  2. LogManager implementation is not friendly to java agents (WFLY-895).

Thus some additional steps required to setup hoopoe.

Domain mode

Edit host.xml:

  1. Set system properties to allow packages to be loaded from bootstrap classloader and to fix log manager:

      <server name="server-one" group="main-server-group">
    <system-properties>
        <property name="jboss.modules.system.pkgs" value="hoopoe.core.bootstrap,org.jboss.logmanager"/>
        <property name="java.util.logging.manager" value="org.jboss.logmanager.LogManager"/>
        ...
    </system-properties>
  ...

  2. Locate jboss-logmanager-*.jar in $JBOSS_HOME/modules/system/layers/base/org/jboss/logmanager/main.

  3. Add jboss-logmanager.jar to boot classpath and enable hoopoe-agent.jar:

      <server name="server-one" group="main-server-group">
    ..
    <jvm name="default">
      <jvm-options>
         <option value="-Xbootclasspath/p:<path-to-log-manager.jar>"/>
         <option value="-javaagent:<path-to-hoopoe-agent.jar>"/>
         ...
       </jvm-options>
    </jvm>
  ...
  ```

Standalone mode

Edit standalone.conf:

  1. Locate the place where JBOSS_MODULES_SYSTEM_PKGS is configured and and the following after that (to allow packages to be loaded from bootstrap classloader):

      JBOSS_MODULES_SYSTEM_PKGS="$JBOSS_MODULES_SYSTEM_PKGS,hoopoe.core.bootstrap,org.jboss.logmanager"

  2. Locate jboss-logmanager-*.jar in $JBOSS_HOME/modules/system/layers/base/org/jboss/logmanager/main.

  3. Add jboss-logmanager.jar to boot classpath and enable hoopoe-agent.jar. Add to the end of the file:

      JAVA_OPTS="$JAVA_OPTS -Xbootclasspath/p:<path-to-log-manager.jar>"
  JAVA_OPTS="$JAVA_OPTS -javaagent:<path-to-hoopoe-agent.jar>"

  4. And finally fix log manager by adding the following to the end of the file:

      JAVA_OPTS="$JAVA_OPTS -Djava.util.logging.manager=org.jboss.logmanager.LogManager"