EGEE Home | Technical Pages Home | Search | EDMS Documents | People | Calendar | Agenda maker | Glossary

JRA1: Workload Management

Tools Testing Integration Information
Services		 Workload
Management		 Data
Management 		Security Management

JRA1 Home | Workload Management Home | Mandate | People | Meetings | Presentations | Savannah Portal| Useful links | Actions list | EDMS



CE Architecture overview


The Computing Element (CE) is the service representing a computing resource.

Its main functionality is job management (job submission, job control, etc.), but it must also provide other capabilities, such as the provision of information about its characteristics and status.

Comparable services from other Grid projects include: the EDG CE, the Alien CE and the Globus GRAM.

The CE, exposing a Web Service interface, may be used by a generic client: an end-user interacting directly with the Computing Element, or the Workload Manager, which submits a given job to an appropriate CE found by a matchmaking process).

A CE refers to a set, or cluster of computational resources, managed by a LRMS.
This cluster can encompass resources.that are heterogeneous in their hardware and software configuration.
When a CE encompasses heterogeneous resources, it is not sufficient to let the underlying LRMS dispatch jobs to any worker nodes.
Instead, when a job has been submitted to a CE, the underlying resource management system must be instructed to submit the job to a resource matching the requirements specified by the user.

The interface with the underlying LRMS must be very well specified (possibly according to existing standards), to ease the integration of new resource management systems (even by third party entities) as needed.
The definition and provision of common interfaces to different resource management systems is still an open issue, but there are proposed recommendations currently under discussion
(such as the Distributed Resource Management Architecture API, DRMAA, currently discussed within the GGF), which are likely to be adopted when they become consolidated standards.

The Monitor (MON) service deals with notifications. It can be customized in particular to:
1- asynchronously notify users on job status events, according to policies specified by users (e.g. when a job changes its status, when a job reaches a certain status, etc.). The jobs to be monitored and the type of notifications to support are stored in the user's UCs;
2- notify about the CE characteristics and status. In particular, for a CE working in pull mode, this service is used to request jobs to the Workload Management Service.
       Disclaimer Contact   Last Modified: Monday, 06-Sep-2004 10:22:55 CEST