ShortTalk - ShortTalk - http://shorttalk.sourceforhttp://shorttalk.sourcefor

ge.net/ge.net/XMPP messaging in a peer to peer XMPP messaging in a peer to peer

mannermannerInstructed by:

Edward Bortnikov

Supervisor: Dr. Ilana David

Developed by: Michael Gartsbein

Project goalProject goal

Create a package that uses the Create a package that uses the XMPP protocol as the transport but XMPP protocol as the transport but distributes the server functionality distributes the server functionality among the participating nodesamong the participating nodes

Create a lightweight XMPP server Create a lightweight XMPP server than can be embedded to each node than can be embedded to each node in systemin system

Develop a demo messaging Develop a demo messaging applicationapplication

MotivationMotivation

To have funTo have fun Explore the filed of Explore the filed of

distributed systemsdistributed systems Experience with the Experience with the

newest open source newest open source development toolsdevelopment tools

Experience …Experience … Experience is what one gets Experience is what one gets

when he doesn’t get what he when he doesn’t get what he wantedwanted

ConstraintsConstraints

OS independence OS independence Use only open source Use only open source

modulesmodules The whole system should be The whole system should be

small and understandable by small and understandable by a single persona single person

The whole system should be The whole system should be delivered as a homogenous delivered as a homogenous python packagepython package

Why distribute?Why distribute? Distributed p2p:Distributed p2p:

Many same or Many same or almost same nodesalmost same nodes

New participating New participating nodes can nodes can contribute resourcescontribute resources

Harder to make Harder to make securesecure

Can be very scalableCan be very scalable Can be very fault Can be very fault

toleranttolerant

Client server:Client server: There are client nodes There are client nodes

and one or (a much and one or (a much smaller) set of serverssmaller) set of servers

There are limitations There are limitations on scalabilityon scalability

New users consume New users consume resources from resources from serversservers

Easier to Easier to monitor/control monitor/control access access

Example of distributed Example of distributed systemsystem

File sharing (torrents)File sharing (torrents) Distributed hash Distributed hash

tablestables Distributed file system Distributed file system MessagingMessaging (skype) (skype) http://http://

en.wikipedia.org/wiki/en.wikipedia.org/wiki/List_of_distributed_coList_of_distributed_computing_projectsmputing_projects

Peer to peerPeer to peer

Natural to use p2p in Natural to use p2p in distributed systemsdistributed systems

Bandwidth and other Bandwidth and other resources sharingresources sharing

Symmetric designSymmetric design ScalableScalable

Many DS are p2pMany DS are p2p

What is XMPP?What is XMPP? Xml based messaging protocol also known as Xml based messaging protocol also known as

jabberjabber Open protocol and internet standardOpen protocol and internet standard Used by google in google-talk and in many Used by google in google-talk and in many

other messaging systemsother messaging systems

*

XMPP (cont. 1)XMPP (cont. 1) XMPP uses a servers based scheme to XMPP uses a servers based scheme to

deliver messages.deliver messages. Sender’s server delivers the message to the Sender’s server delivers the message to the

recipient’s server, and the last to the recipient’s server, and the last to the recipientrecipient

Why python?Why python?

Developing with python is fun!Developing with python is fun! A free and 100% open source platformA free and 100% open source platform OS independent and extra flexible OS independent and extra flexible

languagelanguage linux+unix/mac/win32/winCE+mobilelinux+unix/mac/win32/winCE+mobile

Millions of packages Millions of packages If its good for google, NASA and nokia– If its good for google, NASA and nokia–

it should be good enough for meit should be good enough for me

Why python? (cont.)Why python? (cont.)

Experiencing with new programming Experiencing with new programming paradigm paradigm

Learning new language and new set Learning new language and new set of toolsof tools

ArchitectureArchitecture

Use an open dht system Use an open dht system (bamboo open-dht) for (bamboo open-dht) for the signalingthe signaling

Use the xmpp protocol Use the xmpp protocol at the transport at the transport between nodesbetween nodes

The dht application will The dht application will use a small dht-handler, use a small dht-handler, xmpp client and server xmpp client and server to communicateto communicate

Block schemeBlock scheme

ShortTalk application instance

GUI

XMPP server

XMPP client

DHT handler

User agent

ShortTalk application instance

GUI

XMPP server

XMPP client

DHT handler

User agent

DHT node

P2p session

The technologyThe technology

The project is built as a composition The project is built as a composition of python packagesof python packages

XMPP – client and server according XMPP – client and server according to the XMPP standard RFC 3920to the XMPP standard RFC 3920

DHT – free publicly open DHT DHT – free publicly open DHT service – based on the bamboo service – based on the bamboo projectproject

Tkinter – a “standard” python GUITkinter – a “standard” python GUI

Main technical Main technical milestonesmilestones

Creating a smart and reliable DHT Creating a smart and reliable DHT handlerhandler

Assembling a lightweight XMPP sever Assembling a lightweight XMPP sever engine that will run on both linux and engine that will run on both linux and windowswindows Most of the existing available XMPP Most of the existing available XMPP

servers are pretty heavy and servers are pretty heavy and complicated, and contain features I don't complicated, and contain features I don't need.need.

Main technical Main technical milestones (cont 1)milestones (cont 1)

Embedding XMPP client to the Embedding XMPP client to the projectproject

Assembling the whole system Assembling the whole system together in a demo messaging together in a demo messaging application application

Must do GUI Must do GUI

EntitiesEntities

Typical workflow Typical workflow sequencesequence

Step by step workflowStep by step workflow

Start the Start the applicationapplication Creating the DHT Creating the DHT

handler and handler and choosing a closet choosing a closet DHT node to work DHT node to work withwith

When a the When a the connection breaks, connection breaks, a new one is a new one is transparently transparently establishedestablished XMPP client

DHT handler

User agent

Step by step workflow Step by step workflow (cont 1)(cont 1)

Starting the Starting the XMPP serverXMPP server

Starting the Starting the XMPP client and XMPP client and logging to the logging to the serverserver

Callbacks to Callbacks to GUI are setGUI are set

ShortTalk application instance

GUI

XMPP server

XMPP client

DHT handler

User agent

Step by step workflow Step by step workflow (cont 2)(cont 2)

SubscribingSubscribing User can User can

subscribe to subscribe to DHT handler for DHT handler for event -> other event -> other users go onlineusers go online

Step by step workflow Step by step workflow (cont 3)(cont 3)

Logging to the Logging to the DHTDHT This will create This will create

an entry in the an entry in the DHT with name-ip DHT with name-ip and will refresh itand will refresh it

The user agent The user agent will get will get notifications on notifications on when users will when users will get onlineget online

ShortTalk application instance

GUI

XMPP server

XMPP client

DHT handler

User agent

Step by step workflow Step by step workflow (cont 4)(cont 4)

ChattingChatting User can send a User can send a

message to message to another online another online useruser

The message The message will go from will go from user’s XMPP user’s XMPP client directly to client directly to remote user remote user XMPP serverXMPP server

GUI

XMPP server

XMPP client

DHT handler

User agent

GUI

XMPP server

XMPP client

DHT handler

User agent1 2

3

Look and feelLook and feel

Special thanksSpecial thanks

To Eddie Bortnikov for the whole To Eddie Bortnikov for the whole project concept and supportproject concept and support

To the lab for the infrastructureTo the lab for the infrastructure XMPP community and specially Alexey XMPP community and specially Alexey

"Snake" Nezhdanov for python’s "Snake" Nezhdanov for python’s XMPP supportXMPP support

Open bamboo team for the free DHTOpen bamboo team for the free DHT To sourceforge for hosting and To sourceforge for hosting and

technological supporttechnological support To Guido van Rossum for the languageTo Guido van Rossum for the language

Future developmentFuture development

Embedding the DHT with the Embedding the DHT with the applicationapplication Adding authenticationAdding authentication

Changing the polling of the DHT to a Changing the polling of the DHT to a event driven pub/subevent driven pub/sub

Using DHT to implement “offline Using DHT to implement “offline messaging” and saving user list in the messaging” and saving user list in the gridgrid

Through NAT support Through NAT support

Future Development Future Development (cont.)(cont.)

Contact informationContact information srvrules@t2.technion.ac.ilsrvrules@t2.technion.ac.il

Project developer’s pageProject developer’s page http://sourceforge.net/projects/http://sourceforge.net/projects/

shorttalk/shorttalk/

News from the worldNews from the world

XEP-0174: Serverless MessagingXEP-0174: Serverless Messaging A new standard from October 2008A new standard from October 2008

http://xmpp.org/extensions/xep-0174.htmhttp://xmpp.org/extensions/xep-0174.htmll

Python 3.0 Python 3.0 A new significant release in December A new significant release in December

20082008

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