Middies: Passive middleware abstractionsfor pervasive computing environments

Middies: Passive middleware abstractionsfor pervasive computing environments

Daniel Cutting, Adam Hudson, Aaron Quigley

University of Sydney

Daniel Cutting, Adam Hudson, Aaron Quigley

University of Sydney

Pervasive computing

Middies

Data distribution

Pervasive computing

Middies

Data distribution

Pervasive computingPervasive computing

Small mobile devices + large fixed servers Wireline and wireless communication Application collaboration

chat, file store, video+audio matchmaking, games museum+gallery tours

Small mobile devices + large fixed servers Wireline and wireless communication Application collaboration

chat, file store, video+audio matchmaking, games museum+gallery tours

Art gallery scenarioArt gallery scenario

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.QuickTime™ and a

TIFF (LZW) decompressorare needed to see this picture.

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.QuickTime™ and a

TIFF (LZW) decompressorare needed to see this picture.

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.QuickTime™ and a

TIFF (LZW) decompressorare needed to see this picture.

Edward

BobCynthia

Gillian

Sunflowers, Van Gogh

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

Bob was here.

Bob was here.

MiddlewareMiddleware

Publish-subscribe: good for events

Tuple spaces: good for data persistence

Abstract sockets: good for streaming data

Publish-subscribe: good for events

Tuple spaces: good for data persistence

Abstract sockets: good for streaming data

Pervasive computing

Middies

Data distribution

Pervasive computing

Middies

Data distribution

MiddiesMiddies

Generalised middleware abstractions Features of tuple spaces and pub-sub Store persistent data, publish events and

handle streaming data

Generalised middleware abstractions Features of tuple spaces and pub-sub Store persistent data, publish events and

handle streaming data

SpacesSpaces

Logically centralised shared structures like a tuple space

Physically distributed over several devices

Logically centralised shared structures like a tuple space

Physically distributed over several devices

BlocksBlocks

Data chunks like tuples, events, objects

Stored by spaces permanently (like tuples) or forwarded to interested devices (like events)

Data chunks like tuples, events, objects

Stored by spaces permanently (like tuples) or forwarded to interested devices (like events)

MatchersMatchers

Compare two blocks Application-defined Can implement tuple matchers,

publish-subscribe subscription languages, etc.

Compare two blocks Application-defined Can implement tuple matchers,

publish-subscribe subscription languages, etc.

ReactorsReactors

Callbacks fired by spaces under certain conditions

Can implement events + abstract sockets Useful for pub-sub and streaming data

Callbacks fired by spaces under certain conditions

Can implement events + abstract sockets Useful for pub-sub and streaming data

Pervasive computing

Middies

Data distribution

Pervasive computing

Middies

Data distribution

Data distributionData distribution

How do we distribute blocks around the network?

Server? Single device stores all blocks

Redundant? Each device stores replicas of all blocks

Or…?

How do we distribute blocks around the network?

Server? Single device stores all blocks

Redundant? Each device stores replicas of all blocks

Or…?

Context-aided distributionContext-aided distribution

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.QuickTime™ and a

TIFF (LZW) decompressorare needed to see this picture.

Edward

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

Bob

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.QuickTime™ and a

TIFF (LZW) decompressorare needed to see this picture.

Cynthia

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

Gillian

Unimportant (0.2)Long-lived (0.7)Large size (0.9)

Group photoat Sunflowers

Group photoat Sunflowers

Group photoat Sunflowers

aa

Latitude

sleeping[10,30,2300]working[50,20,0900]v

Nearest situation vector is photophoto digest

Pervasive computing

Middies

Data distribution

Pervasive computing

Middies

Data distribution