Read part one- Revamping Web Applications Part-1 Overview
Read part two- Revamping Web Applications Part-2 Features
We have talked about the Event Networking web application. To start revamping we need to understand the architecture of the existing web application.The current implementation does not follow any architectural patterns like Separation of Concerns, Single Responsibility, Layered approach etc. No planning was done before building the application. We can say that top down approach was followed to develop the current web application. Top down means that the features were added as and when the developer thought it was required. The current application is like a forest of tangled codes.
The current architecture of the application is shown below. The architecture may look like 3 tier in the beginning but really is a 2 tier due to the absence of the Business Objects.
The layers are defines as follows:
1. Presentation Layer: A user can directly access this layer. It comprises of the ASP.Net Web Forms files i.e. aspx. The look and feel and user interface of the web application is also built here.
2. Business Access Layer: BAL encapsulates the business rules and data validation. All the code behind files which we have in our project along with the WCF Data Service are included in this layer. It comprises of the aspx.cs files.
3. Data Access Layer: DAL is the layer to access external data and interact with it. It executes as per the need of the BAL. This layer is the interface between the user and the real Data. The ORMs here include Entity Framework and Linq to SQL.
4. Data: The last layer represents the physical data with which the application interacts. We use SQL Database here. Both Linq and Entity Framework stores and retrieves the data from SQL.
A distinguishing feature of the application is the presence of the WCF Data Service. The Data Service serves to expose the application data to external clients e.g. mobile devices. The Data Service is a read only service and operates independently of the web application. However, it still uses the same database for its data.
The web application doesn’t have the critical functionality of logging, local storage, monitoring and caching.
In this post we have understood the existing architecture. Next, we will perform a web test and discuss various counters and results of the test.
Read- Revamping Web Applications Part-4 : Performance Test