GCore Based Information System Specification

Overview

The Information System (IS) is the core subsystem connecting producers and consumers of resources. It acts as a registry of the infrastructure by offering global and partial views of its resources and their current status and notification instruments.

The approach provided by the IS is of great support for the dynamic deployment capabilities and the interoperability solutions offered by the Resource Management facilities.

Key features

Resource Publication, Access and Discovery

IS is the connecting point among the resources of the e-Infrastructure

Consistency with the new Resource Model

IS grants publication and access to resources compliant with the Resource Model (2nd generation)

Production level QoS - Responsiveness

each query served in milliseconds, thousands of queries served each hour

Production level QoS - Scalability

infrastructures with more than 10K of resources successfully powered

Production level QoS - Reliableness

IS instances have been continuously up for more than one year without human intervention

Support to Standards - WS-DAIX Specification v1.0

full implementation of WS-DAIX v.1.0, a widely accepted standard defining a set of data access interfaces for XML data resources

Support to Standards - XQuery 1.0

Resource discovery can be performed through expressions compliant with XQuery 1.0

Support to Standards - WS-Notifications

Consumers of resources can subscribe to the IS for receiving WS-Notifications about any change occurred in they resources the are interested in

Flexible deployment scenarios

IS components can be deployed in several ways, to best fit the needs of an infrastructure or a specific VO

Design

Philosophy

The IS has been designed and implemented to:

• rely on standards
• support distribution at maximum and replication wherever it is possible
• abstract clients from the deployment scenario

A central role of the Information System is also to publicly manifest resources and connect them to their consumers. A consistent Resource Model has been created at the beginning of the gCube development and served for many years as a solid basis of gCube core-facilities. With the increasing openness of the system, a second generation of the model has been shaped and being integrated in the IS.

Architecture

To deliver the quality of service and performances and to handle growing amounts of information (scalability), the Information System is composed by a set of Web Services and client libraries.

Information System Architecture

• IS-InformationCollector: a service that collects and makes available information related to the actual state of the gCube infrastructure and/or of an assigned subset of it; it exposes APIs compliant with WS-DAIX for feeding and then accessing indexed resources
• IS-Registry: this service exposing an API for publishing/un-publishing of profiles describing resources compliant with the Resource Model of both [Reference_Model|first] and [Resource_Model_(2nd_generation)#Design_Principles|second] generation;
• IS-Notifier:
• IS-gLiteBridge:
• IS-Publisher:
• IS-Client:
• IS-Notification:

Deployment

Usually, a subsystem consists of a number of number of components. This section describes the setting governing components deployment, e.g. the hardware components where software components are expected to be deployed. In particular, two deployment scenarios should be discussed, i.e. Large deployment and Small deployment if appropriate. If it not appropriate, one deployment diagram has to be produced.

Large deployment

A deployment diagram suggesting the deployment schema that maximizes scalability should be described here.

Small deployment

A deployment diagram suggesting the "minimal" deployment schema should be described here.

Use Cases

The subsystem has been conceived to support a number of use cases moreover it will be used to serve a number of scenarios. This area will collect these "success stories".

Less well suited Use Cases

Describe here scenarios where the subsystem partially satisfied the expectations.