1. Metadata Server system software laboratory

2. Overview metadata service in Grid environment Grid environment Metadata server User query data search information reply resource sharing

3. Metadata Server Server components User Interface object publication object deletion query process system status data managementdata access metadata database

4. User Interface User interface will be in the form of web pages  Java-based solution (build a portal with portlets) Power Safety Time-to-market advantage Performance Cost effectiveness

5. User Interface Query process  access the database through the web page  users can search for objects by keywords System status  display system statistics Object publication & deletion  users can access the storage through the web page

6. Database Centralized database We will use mySQL as the database management system After the prototype is done, a decentralized database system will be developed

7. Metadata Structure  a file can belong to only one class  a keyword can belong to only one class  a class can belong to a class fileclasskeyword

8. Metadata Attributes of multimedia files  data identifier (unique)  file name  data type  peer identifier  file owner  class id which this file belongs to  create time  time of last access  multicasting (is this file multicasting or not)  valid (valid or deleted)

9. Metadata Attributes of classes  class id (unique)  class name  parent class identifier (if exists)  valid (valid, or deleted) Attributes of keywords  keyword  class id which this keyword belongs to

10. Metadata Attributes of permissions  file or class id  object type of this permission (file or class)  permission (read, modify)

11. Discussion Replica management How to integrate with other parts of the system  streaming overlay  peer-to-peer storage User management Metadata format