We have a web application(hotel management software) which is developed in classic ASP with SQL server 2012 and it evolved over 8 years to its current form which has 825 of pages(including the process pages), huge database and more than 300 active users going through at least 30 pages per day.
We are using Session ,Cookies ,Query String etc in Application. As this is an existing and working application we do have daily support issue fixes and new enhancement going on in .asp , but we have to migrate this application to ASP.NET MVC .What is best approach and design to continue current application while starting migration in parallel.
Can we use same IIS directory for both .asp and ASP.NET MVC application to host new pages ? How to plan and go ahead with this migration.
We thought of identifying the main modules in this application and rewriting them one by one by separating the application into different layers such as database (existing), then business logic and the view. This way newly developed modules will be added to existing system and new pages will replace old pages in that particular module. At the same time we can test the new layers alongside old system and release them once we feel confident.
Advise with any sample implementation document will be of great help and value.
The code we have now is not written function by function and the design, SQL and functionality code are all in the same page. Help us on the database design also which would support entity framework.