1. AMGA Web Interface Salvatore Scifo INFN sez. Catania
Tutorial per i Neo Assunti del Progetto PI2S2
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2. Partnership
AMGA WI
The AMGA WI Project is carried out by INFN - Catania with the cooperation of the IR&T engineering s.r.l. of Catania ( The context of this work is the TriGrid VL Project ( and the ADAT Project (“Archivio Digitale Antichi Testi).
Trigrid VL Project aims to port several Industrial Use Cases over the Grid Infrastructure and the ADAT Project wants to design and implement a Digital Archive for Cultural Heritage that adopts Grid as a Content Management System (CMS).
Resources
INFN
S. Scifo
IR&T engineering
V. Milazzo
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3. Introduction Grid stores millions files distributed on several sites
Users and applications need a secure, fast and easy to use mechanism to:
organize files in a familiar manner (catalogue service)
find files quickly on the Grid (search engine)
search files using additional information about their contents (metadata attributes)
Metadata Service
allows user to:
associate descriptive attributes with files (metadata)
publish attributes on catalogues
make catalogues available to end users and client applications
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4. AMGA Basic Concepts Attribute – typed couple <name, value>
Name – attribute identifier
Value – attribute value
Type – attribute data type (int, float, varchar, …)
Schema - set of attributes associated with a file
(example: Title varchar, Author varchar, Version varchar, CreationTime timestamp for text files)
Entry – file identifier with the instance of the metadata schema, meaning the values of its attributes
FileA -> AmgaWi presentation, S.Scifo, v.1.00, 25/09/2006
Collection - set of entry
FileA -> AmgaWi presentation, S.Scifo, v1.00, 25/09/2006
File B -> AmgaWi presentation, S.Scifo, v1.01, 25/09/2006
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5. AMGA Service Overview
AMGA (Arda Metadata Grid Application) provides a powerful interface to manage data and their metadata
Schema definition : possibility to define a set of attributes in order to describe the semantic of some entity (example: Dublin Core metadata set describes digital objects published on the Web)
Flexibility : possibility to define dynamic schema in order to support a large number of application domains
Structural metadata : possibility to define hierarchical metadata structures in order to allow collections and sub collections definition
Scalability: possibility to manage a large amount of files and schemas
Security: powerful mechanism to ensure contents privacy and data integrity
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6. Why a Web Interface? Command Line Web Interface Expert User approach:
user account on a Grid UI is needed
net access to the Grid UI (internet eventually) is needed
troubles with Firewalls and security stuff, VPN solution is required
commands have to be typed, well knowledge of syntax is required
no wizards are present, user has to type all commands
user looses the high level view of metadata schemas
Web Interface
User Friendly (Beginner / Intermediate) approach:
no dependence on the Grid UI
only internet accesses is needed
fast and simple training and learning using wizards and encapsulated functionalities (no syntax knowledge is required)
simple and comfortable usage of the service
immediate interaction
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7. High Level Requirement
Access Control
login as AMGA user providing a valid VOMS proxy file
permission for collection management (change mode – change owner)
ACL for collection management (list group, add group, drop group)
Collection Management
collection tree browsing
collection creation
collection deletion
collection ACL management
Metadata management
entry listing / searching
entry creation (insert entry name with attribute values)
entry modification (modify attribute values)
entry deletion
schema management
attribute listing
attribute creation
attribute deletion
Note: all web functionalities are performed according to the business rules of the AMGA Server
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8. Deployment Plan
Application could be deployed on a dedicated server. This can be located inside the GRID network or outside.
Currently the GILDA AMGA Server machine also hosts the web interface.
Users access to the catalog towards the functionalities provided by the web interface.
User uses a common Web Browser.
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9. Software Architecture
Every AMGA logical entity (collection, entry, attribute,..) is mapped to a specific software module.
This ensures a very clean and simple software architecture with an high degree of cohesion and decoupling.
These components work as services invoked by the overlying web pages.
Every component is built on top the Official AMGA Java API.
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10. Functional Tree
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11. Log in
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12. Browsing Collection
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13. Metadata Schema Management
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14. Entry Management
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15. ACL Management
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16. QBE like Query Engine
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17. Query Result
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18. Road Map VOMS Server Integration
Administrative module to manage users and groups
ACL for entries management
Query engine improvement
Common browsers compatibility
Exception Handling improvement
Data/Metadata import/export …
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