Global Accelerator:FAQ about Global Accelerator

If your backend service is deployed on Alibaba Cloud, and the Alibaba Cloud account that you use to deploy the backend service is different from the one that you use to activate GA, but you still want to use GA, take note of the following rules when you configure GA:

• When you activate GA, purchase a basic bandwidth plan that provides enhanced or premium acceleration bandwidth.

• When you configure the endpoint group, select Off Alibaba Cloud for the Endpoint Service parameter.

If you use GA to enable your IPv4 services to support IPv6 clients, you can run the curl command on an IPv6 client to send requests to the backend IPv4 services to test whether the IPv4 services are accessible. Perform the following operations to run a test:

1. In the region of the GA instance, open the command-line interface (CLI) on an IPv6 client.

2. Run the following command to check whether the IPv6 client can access the IPv4 services:

   curl -6 -g http://[<Accelerated IP address assigned by GA>]

   The test result shows that the IPv6 client can access the IPv4 web service by using the accelerated IP address.

Check for the following possible causes:

• Check whether the configurations of your GA instance are complete.

  The GA configurations must include at least one acceleration region, one listener if you use a standard GA instance, one endpoint group, and one endpoint.

• Check whether the client can access the Internet over IPv6.

  You can run the ping command to test the accessibility of the accelerated IPv6 address. If the client cannot access the Internet over IPv6, enable IPv6 and Internet access for the client.

• If you use a domain name to provide services, check whether a DNS record is recently added.

  You can run commands such as dig to check whether an AAAA or CNAME record is added for the domain name. If yes, the AAAA record must match the accelerated IPv6 address assigned by GA, and the CNAME must be mapped to the domain name accelerated by the GA instance. For more information about how to add DNS records, see Configure DNS settings.

• If you use a CNAME record, check whether the region of the client is added to the GA instance as an acceleration region.

  The CNAME assigned by GA is scoped to the acceleration region. In cross-region scenarios, requests may fail. For example, if the acceleration region of the GA instance is the Chinese mainland, requests from outside the Chinese mainland cannot obtain the accelerated domain name that is mapped to the CNAME. We recommend that you add regions that are outside the Chinese mainland to the GA instance as acceleration regions, or use an AAAA record.

• Check whether your website has a security policy or a firewall enabled.

  If a security policy is enabled, allow the public IP address of the endpoint to access the Internet.

• Due to different DNS synchronization times and detection mechanisms, some third-party websites may fail to detect IPv6 support. In this case, you can use an IPv6 client to access the website to check whether the website supports IPv6 clients.

Check for the following causes if you have completed the configurations of your GA instance, which is used to accelerate access to backend services:

• Check whether the backend services are working as expected.

  Send a direct request to the backend services. If an error is thrown by the backend services, check for errors on the origin server.

• If you use a CNAME record to map your domain name, check whether the region of the client is added to the GA instance as an acceleration region.

  The CNAME assigned by GA is scoped to the acceleration region. In cross-region scenarios, requests may fail. For example, if all the acceleration regions of the GA instance are outside the Chinese mainland, requests from the Chinese mainland fail to access the accelerated domain name because it cannot be mapped to the CNAME assigned by GA in the Chinese mainland. We recommend that you add the Chinese mainland to the GA instance as an acceleration region, or use an A or AAAA record.

• Check whether a security policy is enabled for the backend servers.

  Check whether the public IP address of the endpoint is allowed to access the Internet. To view the public IP address of an endpoint, go to the Listener Details tab.

• Check whether the GA instance listens on the service port that points to the service domain name.

  For example, if a service uses both port 80 and port 443, the GA instance must listen on both ports. Otherwise, requests destined for port 80 or port 443 may fail.

• Check whether the origin server is deployed on Alibaba Cloud. If yes, check whether the Preserve Client IP feature is enabled.

  The Preserve Client IP feature requires the origin server to support the Proxy Protocol. Otherwise, requests may fail. For more information, see Preserve client IP addresses. We recommend that you disable the Preserve Client IP feature. For more information, see How do I disable client IP address preservation?

• Check whether the volume of network traffic is within the size of the bandwidth plan.

  You can use the Instance Monitoring feature to check the number of connections and bandwidth usage. High bandwidth consumption may also be caused by DDoS attacks. For more information about instance monitoring, see View the monitoring information of an instance.

• Check whether the GA instance has access control enabled, and whether the client IP address is on the whitelist.

  For more information, see Access control.

• Check whether DNS records are correctly configured, especially whether the accelerated domain name or IP address is mapped to the CNAME or IP address assigned by GA.

  You can run the dig command to check the mappings. For more information about how to configure CNAME records, see Add a CNAME record for a domain name.