1. Meta-Server System Software Lab

2. Overview In the Music Virtual Channel system, clients can’t query for a song initiatively Through the metadata server, we provide the ability to let clients search for songs using metadata – The metadata server stores the lists of songs that will be broadcasted

3. Overview Music Virtual Channel streaming information music stream query Metadata Server client

4. Query – Clients can make a query based on attributes – The metadata describes the streaming music by the attributes such as genre, composer, song name…, etc. – To handle the queries, the metadata server will make a search in the stored data. If a match is found in a one or more broadcast lists, it returns the relative metadata (when will the music be broadcasted, and which channel will broadcast the music) to the client – A failure message is returned if no match was found

5. Query play list Query play list music metadata Metadata Server query result

6. Streaming Information Streaming information – A node that wants to broadcast music will send its play list to the metadata server. It then begin broadcasting after getting a reply from the metadata server sliding window on the stored list – To keep the system synchronized, the metadata server records the time of last update for each broadcasting node. The update message will be dropped if it is older then the newest one this is a very rough synchronization scheme, and we’re working on a better mechanism to keep the system synchronized

7. Streaming Information Metadata Server broadcasting node play list reply msg play list

8. Streaming Information music play list play list sliding window playing will play

9. Streaming Information Stream metadata attributes – streaming root ip – start timestamp Music metadata attributes – song title – subtitle – genre – composer – lyricist – performer – album – copyright – language – song playing time This is not the tables of the database May be edited if need

10. Progress Works done – The centralized database A database built on mySQL system A PHP interface to publish and query Works to do – The sliding window model is still constructing – We are now working on the centralized database, but will develop a decentralized database in the future – The metadata will be represented in XML – An interface based on Java will be developed