What is
load balancing
Load balancing is a computer technology used to distribute load among multiple computers (computer clusters), network connections, CPUs, disk drives, or other resources to optimize resource usage, maximize throughput, The purpose of minimizing response time while avoiding overload.
Several ways of
load balancing are as follows:
(1) HTTP redirection load balancing
The advantage of this load balancing scheme is that it is relatively simple, but the disadvantage is that the browser needs to request the server twice each time to complete a visit, and the performance is poor.
(2) DNS domain name resolution load balancing
The advantage of DNS domain name resolution load balancing is that the load balancing work is handed over to DNS, eliminating the trouble of network management. The disadvantage is that DNS may cache A records and is not controlled by the website.
(3) Reverse proxy load balancing
The advantage is simple deployment, but the disadvantage is that the reverse proxy server is a transit point for all requests and responses, and its performance may become a bottleneck.
(4) IP load balancing
The advantage is that IP load balancing completes data distribution in the kernel process, which has better processing performance than reverse proxy balancing. The disadvantage is that the bandwidth of the load balancing network card becomes the bottleneck of the system.
(5) Load balancing at the data link layer
To prevent the bandwidth of the load balancing server network card from becoming a bottleneck, it is currently the most widely used load balancing method for large websites.
