It has application awareness and can use this additional application information to make more complex and informed load balancing decisions.
It has great feature “Cookie Persistance”
Layer 4 load balancing requires less time and computing resources than Layer 7 , although performance impact is minimal
Load Balance Algorithms (remember as CRRI)
There is a variety of load balancing methods, which use different algorithms best suited for a particular situation.
Least Connection Method — directs traffic to the server with the fewest active connections
Least Response Time Method — directs traffic to the server with the fewest active connections and the lowest average response time.
Round Robin Method — rotates servers by directing traffic to the first available server and then moves that server to the bottom of the queue.
IP Hash — the IP address of the client determines which server receives the request.
About DNS
The Domain Name System (DNS) is the phonebook of the Internet. Humans access information online through domain names, like nytimes.com or espn.com. Web browsers interact through Internet Protocol (IP) addresses. DNS translates domain names to IP addresses so browsers can load Internet resources.
The process of DNS resolution involves converting a hostname (such as www.example.com) into a computer-friendly IP address (such as 192.168.1.1)