Apache UIMA-DUCC (Unstructured Information Management Architecture - Distributed UIMA Cluster Computing ) v.3.0.0 Release Notes

Contents

1. What is UIMA-DUCC?
2. Major Changes in this Release
3. Migration from a Prior Release
4. Limitations

1. What is UIMA-DUCC?

DUCC stands for Distributed UIMA Cluster Computing. DUCC is a cluster management system providing tooling, management, and scheduling facilities to automate the scale-out of applications written to the UIMA framework. Core UIMA provides a generalized framework for applications that process unstructured information such as human language, but does not provide a scale-out mechanism. UIMA-AS provides a scale-out mechanism to distribute UIMA pipelines over a cluster of computing resources, but does not provide job or cluster management of the resources. DUCC defines a formal job model that closely maps to a standard UIMA pipeline. Around this job model DUCC provides cluster management services to automate the scale-out of UIMA pipelines over computing clusters.

2. Major Changes in this Release

Apache UIMA DUCC 3.0.0 is a maintenance release containing new features and bug fixes. What's new:



For a complete list of issues fixed and up-to-date information on UIMA-DUCC issues, see our issue tracker: https://issues.apache.org/jira/issues/?jql=project%20%3D%20UIMA%20AND%20fixVersion%20%3D%20%223.0.0-Ducc%22%20

3. Migration from a Prior Release

When upgrading from an existing installation the ducc_update script may be used to replace the system files while leaving the site-specific configuration files in place. For more information see ducc_update in the Administrative Commands section of the DuccBook.

4. Limitations

On some systems cgroups swap accounting is not enabled and duccmon will show N/A for swap. To confirm, please check memory.stat file in /ducc/ folder. If swap accounting is enabled there should be "swap" property defined. If it's missing, you need to add a kernel parameter swapaccount=1. Details of how to do this can be found here.

Due to a bug in uima sdk, the uima AnalysisEngineProcessException cannot be serialized as a Java object. If your analysis engine throws an exception in process(), the ducc framework will stringify it and wrap it in java RuntimeException. If you have a custom error handler plugged in into a job driver you will not be able to test for AnalysisEngineProcessException in a stack trace with a code like this: if ( error instanceof AnalysisEngineProcessException ) ...

To use OS-based login with the WebServer while running DUCC with IBM java, the minimum JDK version is Java 8 SR4 FP5 (8.0.4.5).