Dependable Pervasive Computing. Roy H. Campbell Systems Research Group University of Illinois at Urbana- Champaign

Transcription

1 Dependable Pervasive Computing Roy H. Campbell Systems Research Group University of Illinois at Urbana- Champaign

2 Active Spaces Application Logic Display Controller

3 Outline! Motivation! Gaia Architecture! Component Management Core! Event Manager!! Data Management! Presence! Security! Application Framework

4 Motivation! User Virtual Space! applications! data! preferences! configurations app Office

5 Virtual space -> Active Space User Virtual Space Discussion Virtual Space Family Discussion Business Meeting Brainstorming Virtual Space Home Active Space Office Active Space

6 Dependability Issues! Active Space Devices! Active Space Infrastructure! s! QoS Provisions! Active Space Applications! Users

7 Gaia Architecture Applications Application Framework Quality of Event Manager File System Security Presence Component Management Core Space Repository Gaia Kernel

8 Component Management Core Applications Middleware Event Manager Application Framework File System Resource Management Component Repository QoS Translation Configuration Management Presence Component Management Core QoS Adaptation QoS Instantiation Space Repository Gaia Kernel

9 Component Management Core! Provides functionality to manipulate components in Gaia:! Creation! Destruction! Uploading! Contains three basic abstractions:! Components! Component Containers! Nodes

10 Component Management Core Active Space Gaia Node Gaia Component Container Gaia Node Gaia Components Gaia Node Examples Gaia Component Container

11 Device Dependability! Lua script boots Active Space using master/alternative configuration files! Gaia Container registers with repository! Components in Gaia Containers register with repository! Keep alive events

12 Event Manager Applications Middleware Event Manager Application Framework File System Resource Management Component Repository QoS Translation Configuration Management Presence Component Management Core QoS Adaptation QoS Instantiation Space Repository Gaia Kernel

13 Event Manager! Loosely coupled communication based on channels.! Supports push, pull, and hybrid mechanisms.! Supports creation of named event channels and distribution of load.! Persistent Events, Databases

14 Event Manager Event Channel Factory 1... Event Channel Factory n Suppliers Suppliers Event Manager Event Channels CreateChannelType DeleteChannelType CreateEventChannel GetEventChannel DeleteEventChannel ListChannelTypes ListEventChannels Consumers Consumers

15 Dependability Issues! Event manager tracks channels! E manager restarted by script! E channels run independent of E manager

16 Applications Middleware Event Manager Application Framework File System Resource Management Component Repository QoS Translation Configuration Management Presence Component Management Core QoS Adaptation QoS Instantiation Space Repository Gaia Kernel

17 -Aware Applications! Situational information, or context, increases richness of communication in human-computer interaction.! Makes it possible to produce more useful computational services.! Example contexts: location, time, weather, stock prices, moods, user activity,

18 ! Provides a taxonomy and uniform representation of context types.! Provides an infrastructure to promote design, implementation, and evolution of context-aware applications.! Ontologies DAML+OIL and Prolog Reasoning Engine.

19 Infrastructure Ubiquitous Applications Inference Inference Engine Engine Synthesizer Synthesizer Engine Engine Provider Provider Provider Provider Provider Provider History History Infrastructure

20 Security and People X Access(X, Display) :- SocialActivity(Room 2401, UbiComp Seminar) IsPresenter(Ubicomp Seminar, X)!if there is a UbiComp Seminar going on in the room, then the presenter has access to the display.

21 Dependability Issues! Reliability of context providers, consumers, channels! engines can reason about temporal, interval logic and about probabilities. What might be useful in run time models?

22 File System Applications Middleware Event Manager Application Framework File System Resource Management Component Repository QoS Translation Configuration Management Presence Component Management Core QoS Adaptation QoS Instantiation Space Repository Gaia Kernel

23 File System! Data Organization:! affects data organization.! Data important in current context is easily accessible.! Can attach context to files and directories.! : situation, location, space, group, time.! Data Transformation:! Applications open data as desired type dynamically typed file system.! System converts data to desired type.

24 Dependability Issues! Availability! Replication! Security Peer to Peer?

25 Questions?

26 References! Manuel Román, Christopher K. Hess, Renato Cerqueira, Anand Ranganathon, Roy H. Campbell, and Klara Nahrstedt, Gaia: A Middleware Infrastructure to Enable Active Spaces. In IEEE Pervasive Computing, Dec 2002! Fabio Kon and Fabio Costa and Gordon Blair and Roy H. Campbell, The Case for Reflective Middleware, Communications of the ACM, 2002, V.45, 6; June, pp ! Manuel Roman and Fabio Kon and Roy Campbell, Reflective Middleware: From Your Desk to Your Hand", IEEE Distributed Systems Online, 2001, V. 2, 5, July.