A new product named google wave is introduced by google.

Introduction

•         Google wave is a Real-Time communication platform

•         It combines aspects of email, instant messaging, wikis, web chat and social networking.

•         Capability of sharing files

Features

•         Real-time: see what someone else is typing

•         Embedded ability : waves can be embedded on any blog or website

•         Applications and Extensions : Developers can build their own applications within waves

•         Playback : we can playback any part of the wave to see what was said.

•         Natural language : can autocorrect the spelling.

•         Drag-and drop file sharing:No attachment ; just drag and drop the file into google wave and every one can acess.

Elements

•         Data model   

•         Operational transformation

Data Model

•         Wave: Each wave has a globally unique id and a set of wavelets

•         Wavelets : Consists of a list of participants

    and  set of  documents

•          Participants: Identified by wave address . It may be a user

•         Document : Having a unique id . Consists of BIBS ie the core part of conversation .

•         Wave view : it is the subset of wavelets in a wave that a particular user has access to it.

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Operational Transformation

•         Core part and is executed in server always.

•         By User-Interface (UI)  real-time processing is performing.

•         Server will wait for the replies at that time  client can perform other operations and when server replies client can sent the operations performed to the server as a  bulk

•         Other clients will get the information from the server itself.

•         After getting the information client will update it.

•         These operations are performed by the operational transformation.

•         Recovery  means are provided for the communication failure or server/client crash

•         Checksum is used for rapid identification of miscommunication.

Architecture

•         Wave provider

     - An organization can act as a wave provider 

      - Individual can run a wave server as a wave provider

      -Identified by internet domain name

      -wave users access all waves through  this

-Two types of wavelets

        -Local

                created by the users of wavelet provider

         -Remote

                 Hosted by other wavelet provider

-Wave provider is UPSTREAM relative to local wavelet and DOWNSTREAM to remote wavelet.

•         Wave store

     - It is the central piece of wave service

     -It  store and resolve wavelet operation  through operational transformation.

     -It is connected to wave server.

•         Wave service

      -serves waves of users and connected to the front-end.

      -two components

          -Federation Gateway

          -Federation Proxy

•         Federation Gateway

     -Pushes new wavelet operation that are applied to local wavelet

•         Federation proxy

     -It receive new wavelet operation pushed , from the wave provider that host the remote wavelet.

Operations performed

•         Clients need to perform these sequence in order

    -Opening a Wavelet

           -client send an open request which contain wave ID and wavelet ID to server 

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-Server-Client Communication

       Server sends to the client

           - a delta / version number

-Client –Server Communication

        Client sends to the sever

             - a delta / version number

•         Recovery

       When communication fails the client starts by reopening the wavelet by sending a history version number received from the server