Oracle Application Architecture

oracle apps uses the internet computing architecture , which is a multitier architecture , create apps uses three tire architecture

there are three seperate tier

1. the desktop tier

2. the application tier

3. the database tier

-----1.THE DESKTOP TIER --

the client interface is provided through the java applet , using java enabled browser

the form client applet must run within the jvm on desktop,  for oracle applcation jvm is supplied by Jinitiator program which works in conjuctoin with browser ,

·    the form client applet is pakaged as java archieve (JAR) files contains all the java classes ,require to run the oracle aplcations forms

·    .jar files one loaded in the browser are stored in the browser cache and need not to be load each time untill update is not available or  untill we dont clear cache .

·    all the automatic downloading and installation is handled by the JInitiator

--------JInitiator --------

·    JInitiator is oracle's java virtual machine (JVM) tha tis implemented on the desktop client as plug in or Active x component (in I.E)

·    when user enter oracle apps url , browser will execute Oracle JInitiator , if its not install brwoser will download it

·    once installed oracle JInitiator will run the forms cleint and start an oralce apps sesson .

--2.THE APPLCATION TIER--

the application tier is location of servers that provide the business logic and code processing , this sometime reffered as middle tier, there are five servers present in application server

1. the web server

2. the forms server

3. the concurrent processing server

4. the reports server

5. the admin server

this application tier provides communication between desktop tier and the database tier . the application tier also controles and handles the load balancing among multiple forms .

1) web server

web server receives  request it receive fom the desktop clients, the web server consist of http listener, load balancer

-it accept incoming HTTP request (URL's) from desktop tier (browser)

- the desktop tier then connect directly to the form server once permited by web server

2)  form server

forms server handles the oracle application forms and the form runtime engine ,

form server displays screen to client side and allow making changes in database records based on user actions

forms server communicate with desktop teir in following ways

--TCP/IP connection

--a standard http connection

--a secure https connection

3)  concurrent processing server most interaction with oracle apps data is done through oracle application forms , bt there are also reporting program and updating program need to be run , to handle these program and to ensure that they do not interfere with interactive operations , they are run on seperate machine called concurrent processing server.

·    processes dat run on concurrent processing server are called concurrent programs, this can operate in the background

3) reports server

the reports server is used to produce reports for oracle business intelligence system

4) Administration server

administration server is machine from which you maintain the data in your oracle application database

---3)THE DATABASE TIER--

·     the database tier holds all the data stored and maintained by the oracle application system

·    in detail the dabase tier contains oracle server files and an oracel applications databse instnace that physically stores the tables , indexes ,

·    database tier does not directly communicate with the desktop tier  but rather it communicate desktop tier by using intermediate tier that is application tier