Applications And Databases
Full Answer Section
System Architectures There are several different system architectures that can be used to connect a web application to a back-end database. Some of the most common architectures include:- Three-tier architecture: This architecture consists of three separate tiers: the presentation tier, the application tier, and the database tier. The presentation tier is responsible for displaying the user interface and handling user interaction. The application tier contains the business logic of the web application. The database tier stores the data that is used by the web application.
- Two-tier architecture: This architecture combines the presentation tier and the application tier into a single tier. The database tier is still separate.
- Monolithic architecture: This architecture combines all three tiers into a single application.
- Performance: Web applications need to be able to respond to user requests quickly. This can be challenging when the web application is connected to a back-end database, as the database needs to be able to process queries quickly.
- Scalability: Web applications need to be able to handle a large number of concurrent users. This can also be challenging when the web application is connected to a back-end database, as the database needs to be able to scale to handle the increased load.
- Security: Web applications are often targeted by hackers. It is important to implement security measures to protect the web application and the back-end database from attack.
- Authentication and authorization: Authentication and authorization mechanisms are used to verify the identity of users and to control their access to resources.
- Input validation: Input validation is used to check that user input is valid and to prevent malicious attacks.
- Output encoding: Output encoding is used to prevent cross-site scripting attacks.
- Firewalls: Firewalls can be used to protect web servers and back-end databases from unauthorized access.
- Use a database server that is optimized for performance.
- Use a caching mechanism to store frequently accessed data in memory.
- Use a load balancer to distribute traffic across multiple database servers.
- Use a database server that can scale horizontally to handle increased load.
- Use a cloud-based database service.
- Use a database sharding technique to distribute data across multiple database servers.
- Keep the web server and the database server up to date with the latest security patches.
- Implement a firewall to protect the web server and the database server from unauthorized access.
- Use a web application firewall (WAF) to protect the web application from common attacks.
Sample Solution
Web Servers and Back-End Databases
General Role of Web Servers
Web servers are software applications that deliver web pages and web-based applications to users. They are responsible for receiving and responding to HTTP requests, which are the messages that are sent between web browsers and web servers.
When a user visits a website, their web browser sends an HTTP request to the web server for the web page or web-based application that they want to access. The web server then retrieves the requested resource from the back-end database and sends it back to the user's web browser.