1September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

TANGO WEB Protocol

2September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

Goals

Tango Web is a new API which allow to access to the Tango System through Internet.

The communication between Application and the Tango Web Server use only HTTP(80) or HTTPs(443) port.

3September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

Parameters

During project development of Tango Web, these goals have been forseen :

Low cost and quick development cycle.Low cost and easy maintenance.Reduce network traffic between client application

and the Tango Web Server.

4September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

Applications launching

5September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

TANGO WEB : General scheme

Tango

Database

JBOSS

DeviceTree

Jive

WEB Browser

Port 80 ou 443

Port 80 ou 443

Port 80 ou 443

FireWall

MachineStatusPort 80 ou 443

LDAP

6September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

TANGO WEB Architecture

TANGO

ATKCore.jar

ATKWidget.jar

TangORB.jar

ATKPanel.jar DeviceTree.jar

7September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

TANGO WEB Architecture

TANGO WEB

WebTangORB.jar

ATKCore.jar

ATKWidget.jar

TangORB.jar

ATKPanel.jar DeviceTree.jar

TangORBServer.war

The applications reach TANGO via Internet thanks to three jars:

-WebTangORB : Data Access Object module.

-ATKAppLauncher : Client side launcher

-TangORBServer : The Tango Web Server Core.

Server

Client

ATKAppLauncher.jar

8September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

WebTangORB

The data access is performed in two steps :

ATK components call WebTangORB components instead of TangORB components.

WebTangORb serializes and sends request to the Tango Web Server .

9September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

Code refactoring

DeviceProxy(Facade)

Private IDeviceProxyDAO deviceProxyDAO

Public … state(…) { }Public … command_list_query (…) { }

Public … get_attribute_property (…) { }Public … write_attribute (…) { }

IDeviceProxy(Interface)

Public … state(…) ;Public … command_list_query (…);

Public … get_attribute_property (…) ;Public … write_attribute (…);

DeviceProxyWEBImpl

Public … state(…) { }Public … command_list_query (…) { }

Public … get_attribute_property (…) { }Public … write_attribute (…) { }

DeviceProxyDefaultImpl

Public … state(…) { }Public … command_list_query (…) { }

Public … get_attribute_property (…) { }Public … write_attribute (…) { }

TangORBCommon

TangORBCommon

TangORBWebTangORB

10September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

Components serialization

A class could be serializable only if it implements the « java.io.serializable » interface.

For non-serializable objects :use of a « remote reference » system.

11September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

The « remote reference » system

The object is store in the http session of the Web Server with a single id.

Only the id is transmitted to the client. The client transfers the id to the server with every subsequent request.

12453

MAP

ID Objet

12453 DeviceData

Serveur Client

12September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

Serveur Internet

Communication protocol

Application cliente

ServletWebServerClient

WebRequest

arguments : Object[]

WebResponse

response : Object[]

Request

Response

13September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

Tango Web Server

Tasks :

Process client requests (Tango device access or database access).

Provide Java Web Start deployment descriptors

Tango Web Server delivery as a War (Web Application Archive) file. This file is deployed on a Java application Server (JBoss).

14September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

Request processing

ProcessAction

Class nameMethod name

Object idMethod name

1- Get the remote referents

process(String objectID…)

1- Create Object

process(String strClass…)

2 – Method call

processMethod(..)

TangORB

5 – Send the results

3 –TangORB process

4 – Store non serializable objects

SerializeObject.serializeObject()

ActionServlet

15September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

War file content

html : html files used by applicationjsp : Java Web Start descriptors (jnlp)img : icons, …lib : downloadable client JAR files.WEB-INF

classes : classes and applications properties fileslib : Server JAR filesweb.xml : Tango Web Server configuration file

16September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

Java Web Start

Use a « jnlp » file to download all resources needed (Jar files, configuration files …).

On each execution Java WS download the last version of the application.

All applications launched with Java WS are executed in a Sandbox much like Applets.

For a total access to the client workstation, the application must be signed.

17September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

An example of TANGO WEB deployment

Tango

Base de données

ServeurJBOSS 2 Serveur

Apache

DeviceTree

Jive

WEB Browser

Port 8080 ou 8443

Port 80 ou 443

Port 80 ou 443

Port 80 ou 443

FireWall FireWall

MachineStatusPort 80 ou 443

Annuaire LDAP

ServeurJBOSS 1

???

FireWall

18September 2007 – Tango Meeting –

D. Baraba-Rossa, M. Ounsy

Any questions?