System Support for Pervasive Applications

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System Support for Pervasive Applications

• Robert Grimm
• New York University
• Presented by
• Manohar Shatha

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About Author

• Assistant professor
• New York University
• PhD from
• University of
• Washington

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Overview

• What is Pervasive Computing?
• Example of Pervasive Computing
• Shortcomings of existing DS
• Unique Requirements of Pervasive Computing
• System Architecture
• Conclusion

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Pervasive Computing?

• Pervasive computing is the next generation
  computing environment with info and communication
  technology everywhere , for everyone at all time.
• Pervasive computing aims to enable people to
  accomplish an increasing number of personal and
  professional transactions using a new class of
  intelligent and portable devices.

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The Biology labAn example application domain

• Goal
• Capture , Organize and Present
• Laboratory processes
• ?

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Unique Requirements of Pervasive Computing

• Embrace Contextual Change
• Application context changes all the time.
• Encourage Ad hoc Composition
• Users expect that devices and application just
  plug together.
• Recognize Sharing as Default
• Applications need to easily share information
  across time and devices.

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Approach to building Pervasive Applications

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Short Comings of existing DS

• Many existing distributed systems seek to hide
  distribution.
• RPC packages , Distributed Object Systems compose
  distributed applications through programmatic
  interfaces.
• Distributed Object systems encapsulate both data
  and functionality with in a single abstraction
  called Objects

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Jini Makesthe Wrong Assumptions

• Jini (and Java RMI) require
• Statistically configured infrastructure
• A well-behaved computing environment
• Transparent and synchronous invocations
• No isolation between objects
• No independence between devices

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Architecture of one.world
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System Services

• Application requires
• Search
• Store data
• Communicate
• Locate
• Fault-Protect
• Move

• System Provides
• Query engine
• Structured I/O
• Remote events
• Discovery
• Check pointing
• Migration

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Discovery

• Rendezvous mechanism
• Finds resources with unknown or changing
  location
• In one.world parlance Locate event handlers
  and routes events to them.
• Supports coping with change and ad hoc
  composition.
• Provides a lookup service mapping resource
  descriptors to event handlers

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Migration

• Moves or copies an application and its data
• In one.world parlance Moves or copies an
  environment and all its contents
• Supports coping with change and ad hoc
  composition
• Captures a checkpoint and then moves everything

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Implementation of one.world

• Written mostly in Java
• Berkeley DB for tuple storage
• Runs on Linux and Windows Systems
• Released as open source
• Current version 0.7.1
• 109,000 lines of code(40,000 statements)
• 400 downloads of source release

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Evaluation

• Landscape project at the University of
  Washington.
• Goal Seamlessly capture, organize and present
  laboratory processes
• Cell System Initiative to one.world
• Has got to be good enough to be used everyday by
  everyone
• Responsive , Stable and Robust.

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Conclusions

• Identified system requirements for new style of
  applications.
• Pervasive applications require support for
  change, composition and sharing.
• Demonstrated a System that satisfies those
  requirements.
• We are at the beginning of a great new era in
  computing.

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Thank You