Methods to Implement HA in a Web Application Server Environment

AB.

The two methods to implement High Availability (HA) in a web application server environment are:

A. Load balancers: Load balancers are used to distribute incoming traffic across multiple servers. When a user requests a web page, the load balancer directs the request to one of the servers that has the least amount of traffic or is most available. This distributes the traffic load across the servers, which increases performance, reduces downtime, and ensures that the application is available even if one or more servers fail.

C. Reverse proxies: Reverse proxies are used to provide an extra layer of security and control over incoming traffic. They act as an intermediary between the user and the web application servers. When a user requests a web page, the reverse proxy intercepts the request and forwards it to the appropriate server. This provides additional security by hiding the IP addresses of the servers from the outside world and allows for more granular control over incoming traffic.

B, D, and E are not methods to implement HA in a web application server environment:

B. Application layer firewalls: Application layer firewalls are used to protect web applications from attacks such as SQL injection, cross-site scripting, and other common web attacks. They do not provide HA for web application servers.

D. VPN concentrators: VPN concentrators are used to provide secure remote access to a network. They do not provide HA for web application servers.

E. Routers: Routers are used to connect different networks together and route traffic between them. They do not provide HA for web application servers.

It is important to note that there are other methods to implement HA in a web application server environment, such as clustering, server redundancy, and geographic redundancy.