đź”—CDAP Components

These are the CDAP components:

  • CDAP Master: Service for managing runtime, lifecycle and resources of CDAP applications (package cdap-master);
  • CDAP Router: Service supporting HTTP RESTful endpoints for CDAP (package cdap-gateway);
  • CDAP Kafka: Metrics and logging transport service, using an embedded version of Kafka (package cdap-kafka);
  • CDAP UI: User interface for managing CDAP applications (package cdap-ui); and
  • CDAP Authentication Server: Performs client authentication for CDAP when security is enabled (package cdap-security).

An optional component is available:

  • CDAP CLI: User interface for interacting with CDAP from within a shell, similar to the HBase or bash shells (package cdap-ui).

Some CDAP components run on YARN, while others orchestrate “containers” in the Hadoop cluster. The CDAP Router service starts a router instance on each of the local boxes and instantiates one or more gateway instances on YARN as determined by the gateway service configuration.

In addition to these components, CDAP uses configuration XML files. The basic configuration is set in the cdap-site.xml file (documented in an appendix). This file is automatically created when you follow the installation procedure steps detailed in later sections. You edit a version of this file to configure CDAP to your specific requirements prior to starting CDAP services.

CDAP generates log files, following the settings in the configuration file logback.xml, using Logback. Logs (for Distributed CDAP) are located in /var/log/cdap. For Standalone CDAP, they are located in <CDAP-SDK-HOME>/logs.

If you have CDAP Security enabled, then you will have an additional file, cdap-security.xml (documented in an appendix), with additional settings.

đź”—Installation Summary

In summary, these are the steps that you follow to install CDAP:

  1. Determine your system architecture
  2. Review and meet the system requirements: hardware, network, and software
  3. Prepare your Hadoop cluster
  4. Install the CDAP components
  5. Configure the CDAP installation
  6. Start CDAP services
  7. Verify the CDAP installation