Table of Contents

Driven FAQ

version 2.0.5

Can I get a free trial version of Driven?

Yes. You can obtain an evaluation version by registering on the Driven Trial registration page. The Driven Trial is available as either an online service hosted on driven.io or as a Driven Server deployment on your own hosting environment.

You can even configure a Driven API key during setup of a Driven Trial version, regardless of which host environment you want to use. By using an API key, you can view aggregated-metric dashboards and tables that help you compare application runs. In addition, the key enables Driven’s team features, which 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.

What should I do if I am prompted for a Driven license when trying to use the trial evaluation version?

Enter the license key in the email from Concurrent after you registered for the online trial program. If you still need to register, go to the Driven Trial registration page. If you registered but cannot find the license key, send an email to support@concurrentinc.com.

Can I run my own Driven Server locally on-premise or remotely at my cloud or hosting provider?

Yes, you can deploy Driven in both environments.

What versions of the JDK are supported?

See the Version Requirements page of the Driven Administrator Guide for information about supported versions.

Does the Driven Plugin affect the execution of the Cascading application?

If your Cascading 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 Cascading MapReduce application.

I am seeing out-of-memory errors. What are the possible causes?

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:

  • Your application is transmitting data to the Driven Plugin at a rate faster than the plugin can send the data to the Driven Server.

  • The Driven Server is unavailable.

  • Your application is unable to connect to the Driven Server.

  • A cluster is inadequately provisioned for NameNode processes and the machine (Driven Plugin pings the NameNode for slice information). Try changing the -Xms and -Xmx settings of your application and NameNode processes to the following: -Xms4096m -Xmx4096m

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 your application.

How can I ensure that I see the application execution data that the Driven Plugin detects?

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 when you run your application:

-Dcascading.management.document.service.archive.dir=/path/to/archive

Or you can set the HADOOP_OPTS environment variable:

> export HADOOP_OPTS="$HADOOP_OPTS -Dcascading.management.document.service.archive.dir=/path/to/archive"

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