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Component-based Computing implications for Application Architectures. Julie A. McCann Imperial College, Department of Computing London UK jamm@doc.ic.ac.uk www.doc.ic.ac.uk/~jamm. Getting to the 3 rd Wave. What is the future of computing? pervasive computing?

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Component based computing implications for application architectures l.jpg

Component-based Computing implications for Application Architectures

Julie A. McCann

Imperial College, Department of Computing

London UK

jamm@doc.ic.ac.uk

www.doc.ic.ac.uk/~jamm


Getting to the 3 rd wave l.jpg

Getting to the 3rd Wave

  • What is the future of computing?

    • pervasive computing?

  • What is the fundamental requirements of such systems?

  • How are we getting there?

    • Go!

    • Hypatia

    • Go! + Hypatia + Jeff’s ADLs = ANS!

Components  ubicom: J.A.McCann, 2002


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Phase I

To the 3rd wave…….

Components  ubicom: J.A.McCann, 2002


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Ubiquitous Computing?

  • Mobile Computing != Ubi

  • Nano Computing != Ubi

  • What is it then?

  • Involves many disciplines.

  • Inspired by the social scientists, philosophers, and anthropologists

  • paradigm shift?

    • currently we expect the user to find ways to use the computer

    • however we currently do not emphasise how the computer can find its own way to serve the user

      • focus on HCI

      • focus on security, privacy --> big brother?

  • Components  ubicom: J.A.McCann, 2002


    Slide5 l.jpg

    Components  ubicom: J.A.McCann, 2002


    Pervasive computing l.jpg

    pervasive computing

    • What is pervasive computing

    • Current technology

    • Mobile computing

    • Context adaptation

    • Intelligent environment

    • Adaptive architecture

    • Security, privacy and management

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    What is pervasive computing l.jpg

    What is Pervasive Computing?

    • Technology View

      • Computers everywhere– embedded into fridges, washing machines, door locks, cars, furniture, people

         intelligent environment

      • Mobile portable computing devices

      • Wireless communication– seamless mobile/fixed

    • User View

      • Invisible– implicit interaction with your environment

      • Augmenting human abilities in context of tasks

    • Ubiquitous = mobile computing + intelligent environment

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Mobility l.jpg

    Mobility

    • Mobile computing

      • Computing & communication on the move

      • Mostly voice based or embedded?

    • Nomadic computing

      • Intermittent connectivity

      • Usual environment available

    • Mobile agents

      • Mobile code and data

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Contents l.jpg

    Contents

    • What is pervasive computing

    • Current technology

      • Current & near term gadgets

      • Wearable computing

    • Mobile computing

    • Context adaptation

    • Intelligent environment

    • Adaptive architecture

    • Security, privacy and management

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Current technology l.jpg

    Laptop

    Personal digital assistant (PDA)

    DoCoMo

    video phone

    Mobile phone / PDA

    http://nooper.co.jp/showcase

    Current Technology

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Current technology 2 l.jpg

    Web Server

    Matchbox computer

    Best friend

    Current Technology 2

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Wearable computers l.jpg

    Wearable Computers

    Watch phone

    Watch camera

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Wearable i o l.jpg

    LCD Jacket

    Wearable I/O

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Designer gear l.jpg

    Designer Gear

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Wearable or luggable l.jpg

    Wearable or luggable?

    See http://wearables.www.media.mit.edu/projects/wearables/mithril/index.html

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


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    Bluetooth

    alternative

    The Whisperer

    • Convert audio signals to vibrations sent via finger

    • Send commands by tapping fingers in various rhythms

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


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    Usability

    • Common user interface for workstation and mobile device applications

      • Adaptive information display

    • Replicate characteristics of paper-based notebooks for annotatablity, robustness, universality

    • Flexible voice based input-output

      • Voice recognition + text to speech conversion

    • Gesture recognition

    • WAP phone is not a useable computing device!!

    • Remove human from loop – intelligent agents?

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


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    Brainwaves!

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


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    Contents

    • What is pervasive computing

    • Current technology

    • Mobile computing

      • Issues

      • Wireless communication

      • Ad-hoc networking

    • Context adaptation

    • Intelligent environment

    • Adaptive architecture

    • Security, privacy and management

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Mobile computing vision l.jpg

    Mobile Computing Vision

    • Universal connectivity – anywhere, anytime

    • Accommodate heterogeneity of networks and communicators

    • Ubiquitous intelligent environment – embedded computers everywhere

    • Easy user interaction

    • Context independent access to services + context dependent information

    Components  ubicom: J.A.McCann, 2002


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    Wireless Communication

    • GSM phone 9.6 Kbps

    • Wireless LAN IEEE 802.11b 200 m range 2.4 Ghz band: 11 Mbps

    • Bluetooth 10 m range 2.4 Ghz band: 1 data (700 kbps) & 3 voice channels

    • UMTS – 3G mobile114 kbps (vehicle), 384 Kbps (pedestrian), 2 Mbps (stationary)

    • HIPERLAN & IEEE 802.11a5 Ghz band: currently 20 Mbps eventually 54 Mbps

    • HomeRF derived from DECT10Mbps

    • InfraRed – direct line of sight: 4Mbs

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Wireless problems l.jpg

    Wireless Problems

    • Too many similar standards

    • Shortage of spectrum Use low power + multiple base stations with intelligent antenna.

    • Overlapping spectrum usage can cause interferenceeg Bluetooth and IEEE 802.11

    • Unregulated bands lead to chaos

    • Health risks?

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Ad hoc networking l.jpg

    Networking with no fixed infrastructure

    Use other devices as routers

    But, security concerns and usage of scarce battery power for relaying – possibly more suited to sensor than user networks

    See http://tonnant.itd.nrl.navy.mil/manet/manet_home.html

    Ad-hoc networking

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Ad hoc network applications l.jpg

    Ad-hoc Network Applications

    • Military battlefield

    • Disaster teams

    • Autonomous robots eg searching buildings, mapping toxic spills

    • Meetings – exchange visiting cards and information

    • Car trains on motorways – 100 KmPH, 2m apartautomatic steering and braking

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Integration of mobile systems l.jpg

    Integration of Mobile Systems

    • Not stand alone devices.

      • Need to interact with complex legacy information systems eg large databases – merging updates, displaying tables etc.

    • Systems development

      • Requirements specification for adaptable systems

      • Component composition to meet global QoS, security, reliability & performance requirements.

    • Mobility models

      • Behaviour specification and analysis

      • Modelling context aware systems

    • Interaction paradigms

      • Event-based not object invocation or RPC

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Contents26 l.jpg

    Contents

    • What is pervasive computing

    • Current technology

    • Mobile computing

    • Context adaptation

    • Intelligent environment

    • Adaptive architecure

    • Security, privacy and management

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Context awareness l.jpg

    Context Awareness

    • Context defined by:

      • Current locationNeed location detection eg GPS or base stationIndoors – radio beacon, IR

      • User activityWalking, driving a car, running for a bus – how to detect this?

      • Ambient environmentIn theatre, alone, in meetingLocal resources or services available

      • Device capabilitiesScreen, input, processing power, battery life ….

      • Current QoS availability– particularly for radio links

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Context adaptation l.jpg

    Context Adaptation

    Server

    • What: Compression, filtering, device-specific transformations, information selection …..

    • Where: Server, proxy or client?

    • Proxy  client and server do not change

    • See Armando Fox work at Stanford

      http://gunpowder.stanford.edu/~fox/research.html

    Proxy

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Map adaptation l.jpg

    QoS &contextadaptation,resourcemonitoring

    Map Adaptation

    • Elements: river, road, motorway, buildings

    • Variants: scale, feature detail, date

    • Dynamic data: road conditions, weather

    Rich & dynamic data,

    Structured data + metadata

    User context based selection,Activity deadlines

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Adapting vector maps l.jpg

    Adapting Vector Maps

    • Maps can be…

      • Split into features and presented in part

      • Encoded at different scales – different feature detail

      • Selective adaptation can consider content being degraded

        See http://www.doc.ic.ac.uk/~dc/

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Mobile medicine healthcare everywhere l.jpg

    Applications

    Automated monitoring

    Implanted devices

    Smart clothing

    Swallow/inject intelligent sensors and actuators

    Accident and emergency support

    Patient record access and integration

    Benefits

    High lower risk monitoring

    Mobility for chronically ill

    Greater out-of-hospital patient management

    Mass data & analysis

    Mobile MedicineHealthcare Everywhere

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Contents32 l.jpg

    Contents

    • What is pervasive computing

    • Current technology

    • Mobile computing

    • Context adaptation

    • Intelligent environment

    • Adaptive architecture

    • Security, privacy and management

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Smart dust l.jpg

    Smart Dust

    • Autonomous sensing and communication in a cubic millimeter – “dust motes”

    • Sensors for temperature, humidity, light, motion ….With bidirectional radio or laser + battery

    • Costs soon < $1

    • Typical Applications

      • Defense related battlefield sensors, motion detectors etc.

      • Inventry control on boxes which communicate with crates, trucks, plane etc to tell you where they are

      • Product quality monitoring – vibration, humidity, overheating

      • Car component monitoring

    • See http://robotics.eecs.berkeley.edu/~pister/SmartDust/

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Smart dust technology l.jpg

    Smart Dust Technology

    Passive laser reflector

    Sensor

    Near

    future

    Current state

    1999

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Future smart dust l.jpg

    Future Smart Dust

    • Intelligent paper with integrated radio replace current displays

    • Smart paint monitors vibrations and detect intruders or changes colour to react to temperature, lighting etc.

    • Intelligent glass can filter sunlight, become opaque  no need for curtains

    • Smart garments or injectable sensors for people monitoring

    • Download design and printable motes for < 1c motewww.media.mit.edu/nanomedia

    • Printable batterieshttp://www.usatoday.com/life/cyber/tech/review/2001-02-12-batteries.htm

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Pervasive computer problems l.jpg

    Pervasive Computer Problems

    • What means of communication?

      Radio – spectrum shortage

      Light based – very directional

    • Batteries would be impractical power source for 100K processors per person. Solar cells are not suitable for all environments.

    • Solar cells + capacitors or rechargeable batteries?

    • Power not speed is the key issue for future processor designs.

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Scaling factors l.jpg

    Scaling factors

    • > 100K computers per person

      • Self organising and self configuring

      • Coherent behaviour from vast numbers of unreliable sensors, actuators and comms. devices

      • Need new techniques for interaction based on biological organisms

    • Exponential Growth?

    94,023 billions per mm2

    By 2100 ……

    425,352,958,651, 200,000,000,000,000,000,000,000Billions of computers

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Intelligent environment 1 l.jpg

    Intelligent Environment - 1

    • Fridge and cupboards tracks consumption and reorder your groceries

    • Your car computer reminds you to pick up your order on the way home when you are near the supermarket.

    Thanks to M. Sloman for slides

    Components  ubicom: J.A.McCann, 2002


    Intelligent environment 2 l.jpg

    Intelligent Environment - 2

    • Lights, air conditioning, TV automatically switch on and off when you enter or leave rooms

    • Sit on your favourite chair and TV switches on to the program you usually watch at this time of the day

    • Use communicator/pda for phone, remote control, keys payments, passport, health records, authenticator.

    • Route input from ‘virtual’ keyboard to nearest suitable display.

    • Automatic detection of new items to control and physical layout in a room or office, using computer vision.

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Vision based interaction l.jpg

    Vision Based Interaction

    Presence: Is anyone there?

    Location: Where are they?

    Identity: Who are they?

    Activity: What are they

    doing?

    Head tracking

    Gaze tracking

    Lip reading

    Face recognition

    Facial expression

    Hand tracking

    Hand gestures

    Arm gestures

    From http://research.microsoft.com/easyliving/

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Contents41 l.jpg

    Contents

    • What is pervasive computing

    • Current technology

    • Mobile computing

    • Intelligent environment

    • Adaptive architecture

    • Security, privacy and management

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Adaptive application architecure l.jpg

    Adaptive Application Architecure

    Remote

    Application

    Servers

    Sensors

    Local & Network

    Intermediate Servers

    Clients

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Policy l.jpg

    Policy

    Rule governing choices in behaviour of the system

    • Derived from trust relationships, enterprise goals and Service level agreements

    • Need to specify and modify policies without coding into automated agents

    • Policies are persistent

    • But can be dynamically modified

      Change system behaviour without modifying implementation – not new functionality

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Policy based adaptive systems l.jpg

    Policy Based Adaptive Systems

    • Authorisation policiesDerived from trust relationships to define what resources or services clients can access, what proxylets or code can be loaded into servers, or what code loaded into the client can do.

    • Obligation PoliciesEvent-condition-action rules to trigger when to perform actions, what alarms to generate etc

    • Ponder– declarative object-oriented languagefor specifying policies.See http://www-dse.doc.ic.ac.uk/Research/policies/

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Example authorisation policy l.jpg

    Example Authorisation Policy

    instauth+ facilities {

    subjectguests;

    targetgym + pool;

    actionenter;

    whentime.between (“0900”, “2100”);

    }

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Example obligation policy l.jpg

    Example Obligation Policy

    inst oblig heartmonitor {

    subject s = medicAgent;

    onheartanomaly (symptom);

    action s.display (messages [symptom]) ->send(alarm, symptom);

    target cardiacCentre;

    }

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Roles l.jpg

    Roles

    • Group of policies with a common subject

    • Defines rights (authorisations) and duties (obligation)

    • Position in organisation – nurse, surgeon

    • Mobile ‘visitor’ roles in hotel or shopping mall – policies which apply to mobile user in an environment

    • Paramedic attending an accident

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Contents48 l.jpg

    Contents

    • What is pervasive computing

    • Current technology

    • Mobile computing

    • Context adaptation

    • Intelligent environment

    • Adaptive architecture

    • Security, privacy and management

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Security l.jpg

    Security

    • Interactions cross multiple organisational boundaries

    • Specification, analysis and integration for heterogeneous OS, databases, firewalls, routers

    • Lessons from history:

      • Cell phones, IR garage doors, CATV decoders

      • Everything worth hacking gets hacked

    • Need for secure ‘out of the box’ set up

    • Identify friend or foe  level of trust

    • Small communicators, with confidential data, are easily lost or stolen – biometric authentication

    • Necessary security technology exists

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Privacy l.jpg

    Privacy

    • Location service tracks movement to within metres(cf mobile phones but pay-as-you-go can be anonymous).

    • Clearly indicate you are being sensed or recorded + user control to stop recording or control distribution of information

    • You are now predictable

      • System can co-relate location, context and behaviour patterns

    • Do you want employer, colleagues or insurance company to know you carry a medical monitor?

    • Tension between authentication and anonymity – business want to authenticate you for financial transactions and to provide ‘personalized’ service cf web sites

    • Constant spam of context dependent advertising

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Management the nightmare l.jpg

    Management – the nightmare!

    • Huge, complex systems

      • Billions of processors

      • Multiple organisations

      • Managing physical world, controlling sensors, actuators

      • Humans will be in the way

    • Errors propagate to bring down complete regions

    • Hacker and virus paradise

    • System propagates false information about individuals or organisation

    • Complexity of s/w installation on a workstation or server – how do you cope with billions?

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Management solutions l.jpg

    Management Solutions

    Policy

    • Intelligent agents, mobile agents, policy

    • QoS Management

      • Fat pipes and large storage can convert media streams to short traffic bursts in core network but still needed for wireless links

    • Adaptive self-management is the only answer

      • Partitioned domains of responsibility

      • Genetic algorithms may be suitable for long-term strategy but need more deterministic solutions for short term decision making

    • Remove human from the loop

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Slide53 l.jpg

    Components  ubicom: J.A.McCann, 2002


    Conclusions l.jpg

    Conclusions

    • Universal PDA/communicator

    • Explosion in embedded sensors/actuators

    • Context-aware intelligent environment

    • Privacy will be a major issue

    • Out of the box security

    • Adaptive self-management is needed – biological paradigms?

    Components  ubicom: J.A.McCann, 2002

    Thanks to M. Sloman for slides


    Phase ii l.jpg

    Phase II

    What needs to change?

    Components  ubicom: J.A.McCann, 2002


    Ubicomp requires l.jpg

    Ubicomp requires:

    • Adaptive, lightweight, flexible systems

    • Like plugging in a light-bulb

  • elegantly be able to cope with one device disappearing and new (perhaps upgrades) devices entering the resource pool.

  • change its characteristics to do many differing tasks on demand.

  • reconfiguring dynamically, self-aware and aware of fellow components.

  • overhead needs to be lightweight and perform well for such technologies to succeed

  • no systems management (self management)

    • Adaptive 

    • Biological 

  • Components  ubicom: J.A.McCann, 2002


    Componentisation l.jpg

    Componentisation

    • Componentisation

      • Breaks down system into components

      • Components are plugged-unplugged with (little or no) warning

      • Component managers make decisions to change components to effect adaptability (using feedback/monitoring)

      • Only components required are loaded -> lightweightness

      • 24X7 potential, graceful upgrade of system where we update component at a time.

    • Requirements

      • Components can be self-aware and autonomous, likewise system is self-aware

      • Component architecture description model (provides component management ‘intelligence’)

      • For performance reasons we need components to build the whole system (i.e. not just the middleware e.g. Corba)

    Components  ubicom: J.A.McCann, 2002


    Adaptivity l.jpg

    Adaptivity

    • Examples of adaptivity

      • Seti/consume model – small devices sharing resources on demand (using up free processing/bandwidth)

      • Robustness- component beginning to fail (hw/sw), manager brings up others to take its place

      • Performance – network bandwidth getting tight, change data encryption, change route to user. Etc etc

    • We are looking at component language description, adaptivity and fine –grained (i.e. OS level) componentisation.

    Components  ubicom: J.A.McCann, 2002


    Phase iii l.jpg

    Phase III

    Proofs of concept

    Components  ubicom: J.A.McCann, 2002


    A solution l.jpg

    A Solution?

    • support improved performance, configurability, flexibility, dynamism, software eng.

    • should be decomposed and support relatively small components

    • Kendra looked at adaptivity

    • performance problems -> course grained components

      • low protection overheads should enable fine -grained protection without sacrificing performance

    • Components = highly adaptive/flexible systems

      • fine-grained componentization

      • paging waste --> 1/2 n P bytes lost to fragmentation

        • n= number of domains, P= page size(bytes)

        • segmentation

    • language independent

    Components  ubicom: J.A.McCann, 2002


    Go a novel operating system l.jpg

    Go! – A Novel Operating System

    • protection model (software-based instruction set reduction) using code scanning

      • code sections scanned before the OS loads them to ensure no privileged instructions are contained.

    • Components invoke services via an ORB (privileged)

      • component management

      • loads segment registers to effect a context switch

      • uses thread migration rather than asynchronous messaging

    Components  ubicom: J.A.McCann, 2002


    Slide62 l.jpg

    Go!

    Client component

    call

    Server component

    return

    • ORB

    Components  ubicom: J.A.McCann, 2002


    Go results l.jpg

    Go! Results

    • GTE is Go!’s proof of concept

    • good results for other temporal and spatial comparisons

    Components  ubicom: J.A.McCann, 2002


    Patia adaptive management system for distributed webservers l.jpg

    Patia: Adaptive Management System for Distributed Webservers


    Objectives l.jpg

    Objectives

    • Build adaptive framework to support high-performance distributed webservers

      • Distribution mechanisms

      • Data placement

      • Request scheduling

    Components  ubicom: J.A.McCann, 2002


    Patia l.jpg

    Stills on a filesystem

    Document/ Presentations

    Streaming Media

    Database data

    Transaction semantics

    Advertising?

    Transaction semantics

    Chat room server

    PATIA

    Web presentations can consist of many varying media and technologies often running concurrently.

    Components  ubicom: J.A.McCann, 2002


    Distributed web servers l.jpg

    Distributed Web Servers

    • Client based distribution

      • Request routed to particular server by client (requires apriority knowledge of set-up.

    • DNS based distribution

      • Resolve URL to IP address (stamped with TTL) sent to client

      • Cached with client and name servers on route

      • caching of information by name servers means any server changes can’t be reflected (lowers adaptivity)

        • – short TTL doesn’t work as most servers discard low TTLs

    Components  ubicom: J.A.McCann, 2002


    Distributed web servers cont l.jpg

    Distributed Web Servers (cont)

    • Dispatcher based distribution

      • Network component of web server selects node

      • Operates at lower level in protocol stack (advertises single virtual-IP address)

      • Typically use round-robin to select server (replicated servers)

    • Server based distribution

      • Uses DNS to select server node

      • Server then does redirection if necessary (overcoming the TTL problem)

      • Poorer performance currently measured for this technique

    Components  ubicom: J.A.McCann, 2002


    Other distributed web servers l.jpg

    Other Distributed Web Servers

    • Content based dispatcher distribution

      • Webserver node chosen depends on the TYPE of request sent by client

    • Caching dispatcher distribution

      • Dispatcher is a cache

    • DNS/Dispatcher-Server based distribution

      • Cluster DNS selects dispatcher (based on proximity to client)

      • Dispatcher select webserver node

      • Webserver node can carry out redirects to other nodes

    Components  ubicom: J.A.McCann, 2002


    Slide70 l.jpg

    Components  ubicom: J.A.McCann, 2002


    Slide71 l.jpg

    Components  ubicom: J.A.McCann, 2002


    Slide72 l.jpg

    Components  ubicom: J.A.McCann, 2002


    Slide73 l.jpg

    Constraint: <rule_conditional>| <rule_selection>

    <rule_ conditional > ::= if <boolean_expression> then

    <action_sequence>

    [ else

    < action _sequence> ]

    end_rule;

    <boolean_expression> ::= <resource> <standard_boolean_expression>

    < action _sequence> ::= < action > [{ ";" < action > }]

    < action > ::= <instruction> "(" <parameter_sequence> ")"

    <parameter_sequence> ::= <parameter> [{"," <parameter>}]

    <instruction> ::= BEST, SWITCH etc....

    <resource> ::= PROC_UTIL or BANDWIDTH etc...

    <standard_boolean_expression> ::= AND, OR, NOT, <, >, etc....

    rule_selection::= case resource of

    { set_expr ":" < action _ sequence >}

    [ else < action _ sequence > ]

    end case_rule;

    Figure 3 BNF format for Adaptivity Rules in Patia

    Components  ubicom: J.A.McCann, 2002


    Slide74 l.jpg

    Components  ubicom: J.A.McCann, 2002


    Slide75 l.jpg

    Fire

    Gawesh and Linxue’s lab

    Components  ubicom: J.A.McCann, 2002


    Ans ubiquitous computing management l.jpg

    ANS ubiquitous computing management

    • mimics an ANS (the Autonomic Nervous System) of living creatures.

    • However, we are unaware of the workings of the organic ANS because it functions in an involuntary, reflexive manner. E.g. heart beats faster.

    • What is particular about the organic ANS is that it is

      • flexible,

      • constantly in operation

      • happens in the background without our interference or knowledge of its mechanism.

    • This is exactly what is needed to support the application of the ‘intelligent home’ and medical applications where constant technical support is impossible.

    Components  ubicom: J.A.McCann, 2002


    Ans cont l.jpg

    ANS cont.

    • Essentially the organic ANS is our body’s resource manager

    • likewise the Ubicomp ANS Manager becomes the a replacement operating system or virtual machine

    • provides the systems’ ability configure and reconfigure itself under differing conditions and ever-changing environments. Further, such a system should provide the ‘intelligence’ to optimise its operation through constant monitoring and tuning to achieve its goal.

       we require the architecture to be composed from lightweight components that co-operate.

    • The expected benefits from the research are a clear and quantifiable set of requirements and more importantly, technological solutions to the problem of running the highly complex systems needed for ubiquitous computing with little or no user intervention for system management and maintenance

    • We believe that solving this problem is key to realizing the ubiquitous computing vision. CALM

    Components  ubicom: J.A.McCann, 2002


    Open questions l.jpg

    Open questions

    • beginning to observe that our system behaves in a similar fashion to that of biological systems.

    • with finer-grained systems there are lots of (tuning) variables, many feedback loops to drive the adaptivity etc.

    • These questions show how exciting the area of ubiquitous computing is and will continue to be,

    • and how it will continue to encompass many diverse computing (and non computing) disciplines.

    Components  ubicom: J.A.McCann, 2002


    References l.jpg

    References

    • CACM May 2000 vol43, no 5

    • Intelligent Environment

      • http://www.media.mit.edu/

      • http://cooltown.hp.com/

      • http://portolano.cs.washington.edu/

      • http://www.firstmonday.dk/issues/issue4_9/odlyzko/

    • Wearable Computers

      • http://www.redwoodhouse.com/wearable/

      • http://iswc.gatech.edu/archives.htm

    • Wireless communications

      • http://www.wirelessdevnet.com/

    • Mobile computing

      • http://computer.org/dsonline/

      • http://www.mobileinfo.com

      • http://www.comp.lancs.ac.uk/computing/research/mpg/most/

    Components  ubicom: J.A.McCann, 2002


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