Before using load balancing, you need to make the following preparations:

1. Determine the region where the load balancing instance is located

It provides load balancing services in Northeast China, North China, South China and North China. How to select a region

Consider the following:

• It is recommended to select the region closest to your customer to reduce delay;
• The load balancing instance should be in the same region as the backend ECS. Load balancing does not support cross regional deployment.

2. Select a listening protocol

support four layers (TCP/UDP protocol) and 7th floor (HTTP/HTTPS protocol).

• TCP transport layer protocol: establish a connection with high reliability and fast transmission speed. Most network connections use this protocol for scenarios with high reliability and data accuracy requirements and relatively low transmission speed, such as email, remote login, and some simple Web applications
• UDP transport layer protocol: establish a connection with low reliability. The transmission speed is very fast. The real-time requirements are high, and the reliability requirements are low, such as news push, message notification, etc
• HTTP application layer protocol: mainly solves how to package data, most commonly Internet Web applications
• HTTPS application layer protocol: encrypt HTTP to prevent unauthorized access. Web applications that need encrypted transmission

be careful:

HTTPS decryption and authentication are completed on load balancing. The back-end ECS only responds to requests, thus improving the efficiency and convenience of the back-end ECS. The certificate management service is provided. After uploading the certificate to load balancing, the HTTPS based load balancing service can be easily configured.

3. Prepare the back-end server

A complete set of load balancing services needs to add servers in the back end of the load balancing instance to handle the front end listening and forwarding requests.

Consider the following:

• The prepared backend ECS should be in the same region as the load balancing instance;
• The prepared backend ECS instances are deployed with relevant applications.

At present, up to 50 back-end servers can be added to the backend of the load balancing instance.