Apache UIMA-DUCC (Unstructured Information Management Architecture - Distributed UIMA Cluster Computing ) v.2.2.2 Release Notes
Contents
1. What is UIMA-DUCC?
2. Major Changes in this Release
3. Migration from a Prior Release
4. Limitations
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.
Apache UIMA DUCC 2.2.2 is a maintenance release containing new features and bug fixes. What's new:
- Upgraded UIMA (2.10.2), UIMA-AS (2.10.2), ActiveMQ (5.15.2), Spring Framework (4.3.9), Camel (2.19.3), XStream (1.4.10)
- Requires java 8 for builds and runtime. User jobs and services must use java 8.
- Fixed rogue process detector to prevent truncation of user names
- Reduced size of publications between the PM and Agents
- Improved Agent's detection of defunct processes
- Improved logging of system events
- ducc_watcher improvements
- Job & managed reservation specs now saved in DB
- DUCC Web Server (WS) queries DB too often
- DUCC Web Server (WS) should use Resource Manager (RM) calculated value for machine's memory available
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%222.2.2-Ducc%22%20
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.
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 wrapt 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).