WTS Agencies

WTS

1.	Based on three tiered application: (presentation, business services-application server, data services)

2.

Architecture goals:

-	Autonomy - govern critical resources
-	Reliability - provide accurate results (ACID)
-	Availability - available to service requests. Eliminate any potential single point of failure
-	Scalability -Linear throughput growth for additional resources
-	Interoperability -Ability to access applications, data or resources on other platforms

3.

How it works:

-	Client does its request to App Server (via DCOM).
-	App Server creates an instance of RDM to attend the client.
-	App Server acts as a Data Retrieval Engine. It accesses data (via ADO), processes it and saves changes.
-	App Server builds response data, sends it to the client, and destroys instance previously created.

4.

Web Enabled. In the case of web application, we re-used all the business logic. It is an extension of client/server architecture

-	Client does its request (HTTP) to Web Server (via Internet).
-	Web Server communicates with App Server (via DCOM) and pass the client request
-	App Server creates an instance of RDM to attend the client.
-	App Server acts as a Data Retrieval Engine. It accesses data (via ADO).
-	App Server builds response data, sends it to the Web Server, and destroys instance previously created.
-	Web Server creates the response web page (HTML) and gives it back to the browser.

5.	Data services optimized for SQL Server.
5.

6.	Reports created using Delphi QuickReport components in the Client/Server version and PDF components in the web version.
6.

7.	Robust security module. Setting security by users or group of users.
7.

8.

Application Design practices:

Avoid Deadlocking and Blocking
-	Smaller more efficient transactions will decrease the occurrence of server blocking and deadlocking as well as network traffic.
Avoid Server cursors
-	Each statement is executed on a row level basis, thereby increasing locks obtained, network traffic and client connection time.
Stateless Application
-	A stateless application will disconnect from the data tier and only reconnect when necessary.
-	Packet records to the Client Side.
Eliminate unnecessary network traffic
-	Use SP and SP with Multiple statements
-	Use small result sets