EdgeOne supports clients to initiate requests using the HTTP/2 protocol. HTTP/2 (i.e., HTTP 2.0, the second version of the Hypertext Transfer Protocol) is the second major version of the HTTP protocol, which can effectively reduce network latency and improve site page loading speed.
Use Limits
Upload scenario: Due to the default flow control window limit in EdgeOne, large file uploads may experience reduced transmission speeds if the window is exhausted. If you need to upload files larger than 512 KB, it is not recommended to enable HTTP/2.
Download scenario: It is recommended to evaluate the flow control window size declared by the client-side or server-side HTTP/2 implementation. If the client-side window is small (for example, in a mobile weak network environment), enabling HTTP/2 may not achieve the expected acceleration effect. The HTTP/2 flow control window is 512 KB.
Note：
1. If the client request does not use HTTP/2, EdgeOne is compatible with HTTP 1.x protocol access.
2. For configuring access requests, please refer to this document. If you need to configure HTTP/2 to follow the origin, please refer to HTTP/2 origin-pull.
All access domains of the current site have been configured with SSL certificates. For instructions on how to configure SSL certificates, see Certificate Configuration.
Directions
Scenario 1: Modify HTTP/2 support for all domain names of the site
If you need to enable or disable HTTP/2 for the whole connected site, please follow the steps below:
1. Log in to the Tencent Cloud EdgeOne console, enter Service Overview in the left menu bar, and click the site to be configured under Website Security Acceleration.
2. On the site details page, click Site Acceleration to enter the global site configuration page. Then click Network Optimization in the right sidebar.
3. Locate the HTTP/2 configuration card. This protocol is disabled by default. Toggle the switch to enable it.
Scenario 2: Enable HTTP/2 for a specified domain name
If you only need to enable or disable HTTP/2 for a specified domain name, please follow the steps below:
1. Log in to the Tencent Cloud EdgeOne console, enter Service Overview in the left menu bar, and click the site to be configured under Website Security Acceleration.
2. On the site details page, click Site Acceleration to enter the global site configuration page. Then click the Rule Engine tab.
3. On the rule engine management page, click Create rule and select Add blank rule.
4. On the rule editing page, select the Host matching type to match requests for the specified domain name.
5. Click Action, and in the pop-up operation list, select the operation as HTTP/2. Click the switch to enable/disable.
6. Click Save and Publish to complete the rule configuration.
HTTP/2 Traffic Statistics
The HTTP/2 protocol switch applies to TLS connections rather than individual domain names. Therefore, when multiple domain names share the same connection, you may see H2 traffic from a domain name for which HTTP/2 is not enabled, or H2 traffic concentrated on a single domain name. This is expected behavior for HTTP/2.
The details are as follows:
Prerequisites: Multiple domain names resolve to the same IP address, and the SAN of the same certificate covers these domain names simultaneously.
1. HTTP/2 traffic is counted based on the SNI domain name used when the connection is established. For example, if both domain names A and B have HTTP/2 enabled, and the SNI domain name used when the connection is established is B, then all HTTP/2 traffic on this connection is counted under domain name B.
2. Assume that HTTP/2 is disabled for domain A and enabled for domain B, and the SNI domain used when the connection is established is A. If domain B reuses this connection to send requests, HTTP/2 traffic will also be counted for domain A, which has HTTP/2 disabled.
