Transcript Architectural Overview

Jini:
an overview
Abdullah Akce
Resul Ceylan
Background:
visualparadox.com
9 November 2005
Abdullah Akce & Resul Ceylan
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Outline
1. Technology overview
a. What is Jini?
b. What Does it Do?
2. Architectural overview
(How Does it Do?)
3. Conclusion
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Technical Overview > What is Jini?
• Jini is a new distributed computing environment introduced
by Sun Microsystems.
• Its main goal is “network plug and play”.
• It enables the building of
• Dynamic
• Flexible
• Easily administered
distributed systems.
• Jini is not an acronym, it does not stand for anything.
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Technical Overview > What is Jini?
• When a new service is added to dynamic runtime environment;
It announces its presence.
• If clients want to use that service;
it can locate it
it can use its available tasks.
• Clients and services communicate with each other by Jini
protocols.
• Jini provides a middleware layer to link these services and
clients.
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Technical Overview > What Does it Do?
• Provides an application level abstraction of networking.
• Client’s functional needs and service’s functional capabilities
are defined in its simplest, flexible form.
• It is used in wide range of applications:
• Edge networking (recover failures at edges automatically)
• Grid Computing (provides scalability)
• Others (Dynamic System Integration, Dynamic Clustering,
Workflow/Message Switching, Ad-hoc Networking, etc.)
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Technical Overview > What Does it Do?
• Two examples:
•Digital Camera and Printer Communication
•Jini enabled desk lamp and alarm clock.
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Architectural Overview > How Jini works?
a Jini device would
automatically broadcast what
the device it was embedded in
could do and how it worked.
Devices can link themselves
and take advantage of each
other's abilities, bypassing the
need for a person to inform all
the affected components.
Source: ‘Sun tries again with Jini’, CNET News.com
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Architectural Overview > Components
• It consists of three components: services, clients and the
lookup service. There is a network connecting them.
LOOKUP SERVICE
TCP/IP
NETWORK
SERVICE
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CLIENT
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Architectural Overview > Registering a Jini Service
A service is represented by a service object.
It is the publicly visible part of the service and will be downloaded to clients.
The Discovery Protocols are used to find out the lookup services.
When lookup service gets a request, it sends an object called registrar back to
the server. This object acts as a proxy to the lookup service.
The Join Protocol happens after the discovery process, and is accomplished by
using the downloaded proxy of the lookup service.
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Architectural Overview > Registering a Jini Service
A service is represented by a service object.
It is the publicly visible part of the service and will be downloaded to clients.
The Discovery Protocols are used to find out the lookup services.
When lookup service gets a request, it sends an object called registrar back to
the server. This object acts as a proxy to the lookup service.
The Join Protocol happens after the discovery process, and is accomplished by
using the downloaded proxy of the lookup service.
Service
Object
Querying for a service locator
LOOKUP SERVICE
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SERVICE PROVIDER
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Architectural Overview > Registering a Jini Service
A service is represented by a service object.
It is the publicly visible part of the service and will be downloaded to clients.
The Discovery Protocols are used to find out the lookup services.
When lookup service gets a request, it sends an object called registrar back to
the server. This object acts as a proxy to the lookup service.
The Join Protocol happens after the discovery process, and is accomplished by
using the downloaded proxy of the lookup service.
Service
Object
Registrar returned
Registrar
LOOKUP SERVICE
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SERVICE PROVIDER
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Architectural Overview > Registering a Jini Service
A service is represented by a service object.
It is the publicly visible part of the service and will be downloaded to clients.
The Discovery Protocols are used to find out the lookup services.
When lookup service gets a request, it sends an object called registrar back to
the server. This object acts as a proxy to the lookup service.
The Join Protocol happens after the discovery process, and is accomplished by
using the downloaded proxy of the lookup service.
Service
Object
Service
Object
Service uploaded
LOOKUP SERVICE
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Registrar
SERVICE PROVIDER
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Architectural Overview > Using a Jini Service
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Architectural Overview > Camera/Printer Example
Proxy
object
Printer
Attributes
Proxy
object
Printer
Attributes
LOOKUP SERVICE
TCP/IP
NETWORK
Printer
Service
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Proxy
object
Client:
Digital
Camera
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Architectural Overview > Camera/Printer Example
1. A new printer is set up in the network.
2. The printer sends a “looking for lookup services” message to the local network.
3. Each lookup service on the network responds with a proxy for itself.
4. The printer registers its proxy object and attributes with each lookup service
using the proxy of each lookup service.
5. A man with a digital camera comes into this network, and he wants to print out
a new picture.
6. The camera sends “ looking for lookup services” messages to the local network.
7. Each lookup service in the network responds with a proxy for itself.
8. The camera searches for types of services it needs using the proxies of one or
more lookup services. The lookup service returns one or more matching proxy
objects, and the client distinguish them further by their attributes.
9. The exactly matched proxy is downloaded to the camera. Then the camera
begins to use the proxy to interact with the printer to print the picture.
Source: ‘The Jini Architecture’, Weisheng Si
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Thank you for your attention!
The END
Abdullah Akce
Resul Ceylan
9 November 2005
Abdullah Akce & Resul Ceylan
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