The basic idea behind SCALEA-G is to develop a system that provides facilities for conducting performance instrumentation, monitoring and analysis of Grid services in Grids. Grid services can be computational resources (e.g. host), networks and applications. Currently, SCALEA-G has been extended to cover also other non-functional parameters (e.g., QoS metrics).

Originally SCALEA-G was implemented as a set of OGSA services based on Globus Toolkit 3.0. However, we have ported SCALEA-G into WSRF-based services using Globus Toolkit 4.0. There are some changes in the architecture; the current architecture is a little bit different from the above figure, however, most components are the same. In current SCALEA-G Implementation we develop:

• Registry Service is based on OpenDHT
• A Directory Service is a WSRF-based service. Directory Service uses Berkeley DB as backend database
• A Sensor Manager Service and a set of sensors for monitoring and measuring performance behavior of Grid services. The Sensor Manager Service is a WSRF-based service that collects monitoring data from sensors, supporting subscription and query monitoring and performance data, etc. The Sensor Manager Service stores its collected data into XML data containers based on DBXML. Sensors are system sensors and application sensors. We also provide sensors that interface to NWS, Iperf, Ganglia, etc., but these sensors provide data back to consumers in XML format
• A Dynamic Instrumentation Service based on C++ gSOAP+ with GSI-plugin and Dyninst. We also develop an Instrumentation Request Language (IRL) to facilitate the interaction between client and instrumentation services. Here are current IRL XML schema and an example of IRL. We have developed a library for parsing IRL based on Xerces C++. Besides dynamic instrumentation, we also support source code instrumentation but manually with C/Fortran code (source code automatic instrumentation service has been removed due to the lack of support from the Vienna Fortran Compiler).
  • a language named WIRL (Workflow Instrumentation Request Language), based on IRL, has been developed for K-WfGrid project. Check our K-WfGrid CVS, under module DR, for the source.
• XML data schemas: All monitoring data is represented by an XML schema. We recently moved SCALEA-G data XML schemas into K-Wfgrid project. These schemas have been improved and contributed to K-WfGrid project.
  • XML schemas and java classes for parsing and unparsing data can be found in our K-WfGrid CVS, under module DR. These parsing classes are based on Castor.
• A Client Service for clients to access SCALEA-G services.
• User GUI. The User GUI uses Askalon Visualization, JFreeGraph for visualizing performance and monitoring data, and JGraph for visualizing execution traces of wGrid workflows under ASKALON
• See SCALEA-G JAVA APIs here.

Demonstration movies

• More will come later
• Modelling, Monitoring and Analysis of Dependability Metrics
• Dependability Analysis in the Portal

SCALEA-G is very different from SCALEA system. This research is partially funded by the Austrian Science Fund as part of Aurora Project under contract SFBF1104, and the IST Working Group Apart under Contract No. EP 29488.