Application server also knows as ‘Instance’, Database Server known as ‘Central Instance’.
The architecture of application server defines as:
All the requests that come from the presentation servers are directed first to the dispatcher. The dispatcher writes them fist to the dispatcher queue. Te dispatcher pulls the request from the queue on first-in , first-out basis. Each request is then allocated to the first available work process.
To perform any processing for a user’s request a work process needs to address two special memory areas i.e. User Context and the program roll area. The user context is a memory area that contains information about the user and the roll area is a memory area that contains information about the user, and the roll area is a memory area that contains information about the program execution.
User Context is responsible for:
- User’s Current settings
- User Authorizations
- The name of the program the user currently is running
Roll Area is responsible for:
- The values of the variables
- The dynamic memory allocations
- The current program pointer
Each time a user starts a program, a roll area is created for that instance of the program. If two users run the same program at the same time, two roll areas will exist-one for each user. The roll area is freed when the program ends.
Roll Area and the user context play an important part in dialog step processing.
The architecture of application server defines as:
All the requests that come from the presentation servers are directed first to the dispatcher. The dispatcher writes them fist to the dispatcher queue. Te dispatcher pulls the request from the queue on first-in , first-out basis. Each request is then allocated to the first available work process.
To perform any processing for a user’s request a work process needs to address two special memory areas i.e. User Context and the program roll area. The user context is a memory area that contains information about the user and the roll area is a memory area that contains information about the user, and the roll area is a memory area that contains information about the program execution.
User Context is responsible for:
- User’s Current settings
- User Authorizations
- The name of the program the user currently is running
Roll Area is responsible for:
- The values of the variables
- The dynamic memory allocations
- The current program pointer
Each time a user starts a program, a roll area is created for that instance of the program. If two users run the same program at the same time, two roll areas will exist-one for each user. The roll area is freed when the program ends.
Roll Area and the user context play an important part in dialog step processing.
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