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6.10. Managing the Agent's Persisted Configuration

The agent uses Java preferences in the Java platform to store its configuration. Java preferences in general are described in the Java documentation at http://download.oracle.com/javase/1.5.0/docs/guide/preferences/index.html. JBoss ON stores user preferences in the backing store's root node.
The location of the backing store depends on the system:
  • On Windows, the backing store is located in the Windows registry.
  • On Linux and Unix systems, the backing store is in the agent user's home directory, in ~/.java.

    Important

    The agent's configuration is determined by what user is running the agent. If the agent is run as one user and then later run as another user, the agent will have a different configuration that second time because it will use a different backing store for its configuration settings.
    For example, if the agent is configured by a system user named jsmith, its persisted configuration is in ~jsmith/.java. If the agent is then configured to run as a background service as the root user, the agent looks for its configuration in ~root/.java, and it finds different configuration settings.
    This means that if one user is used to configure the agent when it is installed, that same user must be used to run the agent subsequently, or the agent will apparently lose its configuration and need to be reconfigured under the new user.
The agent gets the configuration that it uses to run from its backing store. It only reads configuration settings from the agent-configuration.xml file when the agent needs to initialize its backing store, either at its first configuration or if the agent was started with --cleanconfig and fresh configuration settings should be loaded.

6.10.1. Viewing the Persisted Configuration

Agent configuration is comprised of Java preferences, which are persisted for each JBoss ON user. The way that the configuration is persisted depends on the operating system; Windows stores the configuration in the registry, for example, while Unix keeps it in the user's home directory.
The agent configuration is loaded when it is first set up and then persisted in the database, with the exception of a few parameters which can be set and loaded through the rhq-agent-env.sh file. The agent's persisted configuration can be viewed in several different ways:
  1. If the agent is in the JBoss ON inventory, then its complete configuration settings are visible through the Configuration tab, with collapsible tables that display each configuration area.
  2. The configuration can also be returned through the getconfig or config prompt commands for the agent. These commands can be run through a terminal, if the agent is running through a command prompt, or through the Execute Command Prompt operation in the JBoss ON UI for the agent resource. 
    > getconfig  
rhq.agent.agent-update.enabled=true
rhq.agent.client.command-preprocessors=org.rhq.enterprise.agent. SecurityTokenCommandPreprocessor: org.rhq.enterprise.agent. ExternalizableStrategyCommandPreprocessor
rhq.agent.client.command-spool-file.compressed=true
rhq.agent.client.command-spool-file.name=command-spool.dat
rhq.agent.client.command-spool-file.params=10000000:75
rhq.agent.client.command-timeout-msecs=600000
rhq.agent.client.max-concurrent=5
rhq.agent.client.max-retries=10
rhq.agent.client.queue-size=50000
rhq.agent.client.queue-throttling=200:2000
rhq.agent.client.retry-interval-msecs=15000
rhq.agent.client.send-throttling=100:1000
rhq.agent.client.server-polling-interval-msecs=60000
rhq.agent.configuration-schema-version=5
rhq.agent.configuration-setup-flag=true
rhq.agent.data-directory=data
rhq.agent.disable-native-system=false
rhq.agent.name=localhost.localdomain
rhq.agent.plugins.directory=plugins
...
  3. The agent configuration is persisted in Java preferences, so any tool which examines Java preferences can be used to view the persisted configuration.

Warning

Do not attempt to change the values of the preferences using third-party tools. Setting an agent preference to a bad value can completely disable the agent.