Driven FAQ

Driven beta releases are incremental builds of the product before general release of the final version. Hosted versions let you preview and test new features without installing the Driven Server because the driven.io service hosts the server.

An anonymous implementation of Driven has limited functionality. For example, if you download and install the beta Driven Plugin without registering, you can view data about individual application instances but not aggregated-metric dashboards and tables that help you compare application runs. However, an anonymous hosted environment can be an easier way to first use the product.

When you sign up at the Hosted Driven registration page and configure the Driven API key, you can view compilations of application runs and other data with filtering capabilities. In addition, a registered hosted environment can use Driven’s teams feature. The additional capabilities are useful for categorizing applications according to lines of business or for comparing historical execution behavior across the same class of applications to identify outliers and trends.

Yes, you can deploy Driven in both environments with a trial license, which you can obtain on the Driven Trial registration page.

Driven works with any version of Hadoop that is compatible with Cascading. See the Cascading compatibility matrixes for the full list of supported versions.

The matrix of supported JDKs is on the Cascading compatibility matrices page.

If your application executes successfully without the Driven Plugin, it executes successfully whether or not the Driven Plugin transmits all the telemetry data successfully. The push of the data to the Driven Server is decoupled from the execution of the MapReduce application.

The multilayered Driven web client renders much of the application performance data that the plugin sends. Provided that the Driven Server and the plugin are operational and connected, you should not typically need to go beyond the Driven graphical user interface to discover the information that you need.

An "archive mode" configuration is available for the plugin, which writes to disk all data that is sent by the plugin. The archive can be "replayed" to view the information in a log-like format. Archive mode allows you to view data transmitted from the plugin when the Driven Server is not functioning or cannot be accessed. The archive also provides additional details of application execution that are not displayed in the Driven web client.

To use archive mode:

Either pass the following JVM property to the job:

Or you can set the HADOOP_OPTS environment variable:

The compressed archive files are saved to path names that consist of the application name and the ID. Do not use ~ expansion for the path.

By default the Driven webapp uses standard directories that should be accessible to any webapp. If your particular installation does not allow this Driven can be configured to store data somewhere other than the /var/lib/tomcat7/driven default and to write logs somewhere other than the /usr/share/tomcat7/logs default.

OOM messages from the Driven Plugin are most likely a symptom of an error rather than an error itself.

Some possible underlying reasons for the OOM messages are:

If your application executes successfully without the Driven Plugin, it will execute successfully whether or not the Driven Plugin transmits all the telemetry data successfully. The push of the data to the Driven Server is decoupled from the execution of the MapReduce application.

This is an issue with Java’s Preferences handling and some OS setups. The user your webapp runs under (typically tomcat or tomcat7) needs write permissions on its home directory.