PEAR (Processing Engine ARchive) is a new standard for packaging UIMA compliant components. This standard defines several service elements that should be included in the archive package to enable automated installation of the encapsulated UIMA component. The major PEAR service element is an XML Installation Descriptor that specifies installation platform, component attributes, custom installation procedures and environment variables.

The installation of a UIMA compliant component includes 2 steps: (1) installation of the component code and resources in a local file system, and (2) verification of the serviceability of the installed component. Installation of the component code and resources involves extracting component files from the archive (PEAR) package in a designated directory and localizing file references in component descriptors and other configuration files. Verification of the component serviceability is accomplished with the help of standard UIMA mechanisms for instantiating analysis engines.

PEAR Installer is a simple GUI based Java application that helps installing UIMA compliant components (analysis engines) from PEAR packages in a local file system. To install a desired UIMA component the user needs to select the appropriate PEAR file in a local file system and specify the installation directory (optional). During the component installation the user can read messages printed by the installation program in the message area of the application window. If the installation fails, appropriate error message is printed to help identifying and fixing the problem.

After the desired UIMA component is successfully installed, the PEAR Installer allows testing this component in the CAS Visual Debugger (CVD) application, which is provided with the UIMA package. The CVD application will load your UIMA component using its XML descriptor file. If the component is loaded successfully, you'll be able to run it either with sample documents provided in the <UIMA_HOME>/docs/examples/data directory, or with any other sample documents. See CASVisualDebugger.pdf in the docs directory for more information about the CVD application. Running your component in the CVD application helps to make sure the component will run in other UIMA applications. If the CVD application fails to load or run your component, or throws an exception, you can find more information about the problem in the uima.log file in the current working directory. The log file can be viewed with the CVD.

PEAR Installer creates the setenv.txt file in the <component_root>/metadata directory. This file contains environment variables required to run your component in any UIMA application. For instance, if you want to run your component in the Collection Processing Engine Configurator GUI application, you need to add the environment variables settings from the component's setenv.txt file to the cpeGui.bat (cpeGui.sh) script file in the <UIMA_HOME>/bin directory.