Shared Service

1
Shared Service

• A New Paradigm Shift

ECE 497 Cluster Computing Jay R. Moorman Dec.
13, 1999
2
Introduction

• Motivation
• Service Sharing Models
• Comparison
• Key Issues

3
Motivation
User-Centric
4
Components

• Distributed Ad-Hoc Network
• User Require Services
• Computation, Printing, Telephony, Routing, etc...
• Devices Offer/Request Services
• Administration free
• Necessary Network Support
• Infrastructure

5
Service Sharing Models

• Jini
• CORBA
• Bluetooth
• UPnP
• Salutation
• Ninja
• SLP

6
Jini

• Sun Microsystems
• Based on Java Platform
• Federation
• Services
• Java Objects
• Infrastructure
• Discovery, Join, Lookup
• Programming Model
• Leases, Events, Transactions

7
Jini Federation
8
CORBA

• Object Management Group
• 3Com, Canon, HP, Phillips, Sun
• Middleware Software Layer
• ORB
• Client Invokes Method on Server
• Performs Translation
• Includes Discovery Services

9
CORBA Architecture
Interface Definition Language
10
Bluetooth

• Bluetooth SIG
• Ericsson, IBM, Intel, Nokia, Toshiba
• (3Com, Lucent, Microsoft, Motorola)
• Short Range Radio
• Embedded Mobile Market
• MAC Layer Protocol
• Service Discovery Protocol
• Separate Client/Server Connection

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Bluetooth SDP
Service Search Capabilities Match for UUID
Service Handle
List of Service Attributes
12
Universal Plug-n-Play

• UPnP Forum
• Microsoft, 3Com, HP, Intel, IBM, Motorola
• Host/Peripheral Setup
• Web Based with XML
• Simple Service Discovery Protocol
• Discover Service
• Receive XML Schema
• No Program Model

13
UPnP Architecture
Multicast Request Directory Proxy
Service URL Location, Expiration
14
Salutation

• Consortium
• Canon, HP, IBM, Sharp, Toshiba
• Service Discovery Solution
• Salutation Manager
• Service Broker
• Service Capabilities
• Session Management
• Unique SLM ID

15
Salutation Architecture
Capabilities Exchange Protocol
Local Registry Info
16
Ninja

• Berkeley
• Infrastructure Support
• Web Based with XML
• Secure Service Discovery Service
• Certificate Authority
• Capability Manager
• Hierarchical Server Support

17
Ninja Architecture
Persistent State
Session
Soft State
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SDS Architecture
Authenticate Binding Sign Certificates
Limit Access
Query
Announcement
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Service Location Protocol

• RFC 2165
• Local Service Protocol
• Agents Facilitate Interaction
• Service Agents
• User Agents
• Directory Agents
• Logical groupings - Scopes

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SLP Architecture
Service Specific Multicast
Acquire Service Information
Listen
Register
Unicast
iSLP Accept User Requests Deny Service
Registrations
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Comparison

• Security
• Scalability
• Adoptability
• Fault Tolerance

22
Security

• Jini - Based on Java RMI Security Extension
• User Authentication, Access Control, Delegation
• Federation members agree on trust
• CORBA - Object Adapter (Domain Dependant)
• Client Auth, Access Control, Del, Encryption,
  Security Log
• Bluetooth - Link Level Device Authentication,
  Security Manager
• UPnP - Not addressed
• Salutation - Brief ( Authentication, Encryption)
• Ninja - Client/Service Authentication, Implicit
  Server Trust
• Certificate Authority, Capabilities Manager
• SLP - Authentication (URLs, Directories,
  Registration/Deregistration)
• Encryption, Confidentiality (certificate
  authority)

23
Scalability

• Jini - Lookup Service/Lookup Service Interaction
  (Heirarchical?)
• Global UUID naming
• CORBA - Backbone ORBs
• Object Reference Translation Across ORBs (DO.RO)
• Bluetooth - Global UUIDs
• UPnP - Directory/Directory Communication
  (Hierarchical?)
• Global Unique IDs (UDN - Unique Device Names)
• Salutation - Central Server (Need global search
  algorithm)
• Ninja - Server Hierarchy, Hashing requests,
  Naming?, Security?
• SLP - Central Directory with Wide Area Support
• Unscoped services registered everywhere,
  discovery to specific domains

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Adoptability

• Jini - Java based (APIs RMI)
• Many layers for embedded applications
• CORBA - Any operating system Programming
  language
• Compile-time implementation
• Bluetooth - Fast service discovery Good for
  embedded devices
• Requires new stack Very wireless based
• UPnP - Open standard Existing protocols (XML,
  URL, HTTP, IP)
• Specification details
• Salutation - Open standard (processor, OS, comm.
  protocol)
• Uses RPCs Specification details
• Ninja - Existing protocols (XML) / Security
  Implementation
• SLP - RFC Existing protocols (URLs) / Lacking
  industry backer

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Fault Tolerance

• Jini - Service Leasing Peer lookup
• CORBA - ORB Failure?
• Bluetooth - System adjusts to out of range
  servers
• SDP server will co-locate with client/service
• UPnP - Service expiration through caching
• Salutation - Periodic availability check
• Ninja - Service registration timeouts
• SLP - Service lifetime registrations
• Client notification if directory and/or services
  disappear
• Redundant directories

26
Key Issues

• Common
• Future Work

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Common Architecture
Query
Advertise
Leased Service Attributes
Noncompliant Devices
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Future Work

• Paradigm Shift
• Device based to Service based
• Encompassing View
• End Service Computation Middle Support
• Scalability
• Global search Global naming
• Adoptability
• Security Current Protocols Industry
• Fault Tolerance

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END OF PRESENTATION