Alibaba Cloud CDN supports the following types of origin servers: Object Storage Service (OSS) endpoints, IP addresses of origin servers, domain names of origin servers, and Function Compute domain names. You can specify one or more origin servers of each type and specify primary and secondary origin servers to balance loads. This topic describes how to add an origin server, modify the information about an origin server, and configure a health check policy for an origin server.
When Alibaba Cloud CDN retrieves resources from an origin server, the origin server is billed for data transfer. For example, if the origin server is a data center, the data center is billed for data transfer and bandwidth resources. If the origin server is an Object Storage Service (OSS) bucket, the OSS bucket is billed for data transfer.
Add an origin server or modify the information about an origin server
- Log on to the Alibaba Cloud CDN console.
- In the left-side navigation pane, click Domain Names.
- On the Domain Names page, find the domain name that you want to manage and click Manage in the Actions column.
- In the Origin Information section, click Add Origin Sever in the upper-left corner of the origin server list
or click Modify in the Actions column.
- To add an origin server, click Add Origin Server in the upper-left corner of the origin server list.
- To modify the information about an origin server, click Modify in the Actions column.
Parameter Description Origin Info
Select the type of the origin server and enter the address of the origin server.
- Address length: The address of an origin server cannot exceed 67 characters in length.
- Maximum number of origin servers: You can set a maximum of 20 origin server addresses for each accelerated domain name.
- OSS Domain Name
Note Discounts for data transfer between Alibaba Cloud CDN and OSS:
- If you use an Object Storage Service (OSS) bucket as the origin server, you can enter
the public endpoint of the OSS bucket, for example,
***.oss-cn-hangzhou.aliyundoc.com. Internal endpoints of OSS buckets are not supported.
- To view the public endpoint of an OSS bucket, log on to the OSS console. You can also select the endpoint of an OSS bucket that belongs to the current Alibaba Cloud account from the Domain Name drop-down list.
- If you want OSS to identify network traffic sent from Alibaba Cloud CDN and apply for a discount on the data transfer, you must set the origin server type to OSS Domain in the Alibaba Cloud CDN console.
- If you set the origin server type to Site Domain in the Alibaba Cloud CDN console, OSS identifies network traffic sent from Alibaba Cloud CDN as outbound data transfer over the Internet. In this case, the discounts do not apply.
For more information, see Billing of OSS content acceleration.
- If you use an Object Storage Service (OSS) bucket as the origin server, you can enter the public endpoint of the OSS bucket, for example,
- IP: Enter the public IP addresses of one or more servers. Public IP addresses of Alibaba Cloud Elastic Compute Service (ECS) instances do not need to be reviewed.
- Site Domain: Enter the domain names of one or more origin servers.
- The origin domain name must be different from the accelerated domain name. Otherwise, a DNS resolution loop occurs, and requests cannot be redirected to the origin server.
- The format of the origin domain name:
- The domain name must be 1 to 67 characters in length,
- and can contain lowercase letters, digits, and hyphens (-). Example: example.com.
- The domain name cannot contain Chinese characters, uppercase letters, or characters other than hyphens (-). The domain name cannot be a hyphen (-). A hyphen (-) in a domain name cannot be followed by another hyphen (-). The domain name cannot start or end with a hyphen (-). If the domain name contains Chinese characters such as 阿里云.网址, you must apply for an ICP number for the domain name in Chinese characters, and use the tool Punycode to convert the domain name from Chinese characters to English letters, such as xn--fiq****.xn--eq****. Then, you can specify it as the domain name to be accelerated.
- You cannot add the IP address of an Alibaba Cloud Application Load Balancer (ALB)
instance, for example,
example.hangzhou.alb.aliyuncs.com, as the IP address of an origin server. However, you can configure a CNAME record for an ALB instance to resolve a service domain name, for example,
origin.example.com, to the address of an ALB instance. For more information, see Configure a CNAME record. Then, set the service domain name to domain name of the origin server that is accelerated by Alibaba Cloud CDN.
- Function Compute Domain: Enter a Function Compute domain name that belongs to the current Alibaba Cloud account. You must set the Region and Domain Name parameters for the Function Compute domain name. For more information, see Configure a custom domain name.
You can set priorities to specify primary and secondary origin servers. The primary origin server has a higher priority than the secondary origin servers. Alibaba Cloud CDN preferentially redirects requests to the primary origin server. If a fault occurs on the primary origin server, requests are redirected to the secondary origin server. The priority ranges from 0 to 127. A smaller value indicates a higher priority. By default, the priority of the primary origin server is 20, and the priority of the secondary origin server is 30. If you want to set the priority to other values, Submit a ticket.
For example, you have specified two origin servers: Origin Server A and Origin Server B. Origin Server A is the primary origin server and Origin Server B is the secondary origin server. In this case, Alibaba Cloud CDN preferentially redirects requests to Origin Server A. If Origin Server A fails, Alibaba Cloud CDN redirects user requests to Origin Server B. After Origin Server A recovers, Alibaba Cloud CDN redirects user requests to Origin Server A.
WeightIf origin servers have the same priority, Alibaba Cloud CDN redirects requests to the origin servers based on their weights. This balances loads among the origin servers. You can specify a weight based on your business requirements.
- The valid values of origin server weights range from 1 to 100. A greater value indicates a higher weight. An origin server with a higher weight receives more user requests.
- The default value is 10.
For example, both Origin Server A and Origin Server B are specified as primary origin servers. The weight of Origin Server A is 80 and the weight of Origin Server B is 20. In this case, Alibaba Cloud CDN redirects user requests to both origin servers at a ratio of 8:2.
PortSpecify a port on the origin server to process requests. The default port is port 80. You can specify a port based on the settings of your origin server. Valid values are 1 to 65535.
- Default value: 80.
- If you specify port 443, requests are redirected to the origin server over HTTPS. If you specify port 80 or a custom port, requests are redirected to the origin server over HTTP.
- If you want Alibaba Cloud CDN to redirect HTTPS requests to origin servers over custom ports, Submit a ticket.
- If Origin Protocol Policy is enabled, custom ports do not take effect. For more information about how to disable the origin protocol policy, see Configure the origin protocol policy.
- If the origin server is an Object Storage Service (OSS) bucket, OSS determines whether you can specify a custom port.
- Click OK.
Configure a health check policy for an origin server
CDN edge nodes provide Layer 4 (TCP) health checks on origin servers. CDN edge nodes perform health checks on origin servers to check the availability of the origin servers in case back-to-origin routing fails.
- Probes are sent to IP addresses. If the address of an origin server is a domain name, Alibaba Cloud CDN accesses the secondary origin server only if all the IP addresses that belong to the domain name are unavailable.
- Probes automatically skip origin servers that are in the dead table.