This topic describes how to use Global Accelerator (GA) to accelerate a specified domain name.

Scenario

The following scenario is used as an example in this topic. The headquarters of a company is located in the US (Silicon Valley) region. A web service is deployed on two self-managed servers. The web service can be accessed through domain name www.example.com and port 80. When users from the office in the China (Hong Kong) region access the web service deployed in the US (Silicon Valley) region over the Internet, the network condition is unstable. Issues such as network latency, network jitter, and packet loss may occur. Accelerate a specified domain name

You can purchase a GA instance to accelerate network traffic from users in the China (Hong Kong) region to servers in the US (Silicon Valley) region through an accelerated IP address. GA forwards user requests to the global transmission network of Alibaba Cloud and then uses intelligent routing to route the requests to the endpoints in the US (Silicon Valley) region.

Procedure

Accelerate a specified domain name

Step 1: Purchase a GA service bundle

You can enter the information about the web service in the GA console. After you enter the information, the system generates a list of recommended services. The list includes a GA instance and a basic bandwidth plan.

  1. Log on to the Global Accelerator console.
  2. In the upper-right corner of the Instances page, click Purchase Guide.
    Note If this is the first time that you use the GA service, skip this step.
    Purchase Guide
  3. In the Enter the required information to generate a list of recommended services section, enter the required information and click Generate Service List.
    Parameter Description
    Acceleration Area Select the region that requires acceleration.

    In this example, China (Hong Kong) is selected.

    Service Region Select the region where the backend servers are deployed.

    In this example, US (Silicon Valley) is selected.

    ICP Filing Specify whether you have applied for an Internet Content Provider (ICP) number for the domain name of the web service.

    In this example, No is selected.

    Note All websites must obtain an ICP number before they are allowed to provide services to users in mainland China. For more information, see What is an ICP filing?.
    Server Area Specify whether the web service is deployed on Alibaba Cloud.

    In this example, Off Alibaba Cloud is selected.

    Peak Bandwidth Range Enter the bandwidth required during peak hours. Unit: Mbit/s.

    In this example, 2 is entered.

    Maximum Concurrent Connections The maximum number of concurrent connections that a GA instance supports. When the number of existing concurrent connections reaches the upper limit, new connection requests are dropped.

    In this example, 5 Thousand is selected.

  4. In the Recommended Service List section, click Generate Service List after you confirm the information.
    Generate Service List
  5. On the buy page, set the following parameters and click Buy Now to complete the payment.
    Parameter Description
    Term Select the subscription duration.
    Specification Select a specification for the GA instance.

    In this example, Small I (Specification Unit) is selected.

    Bandwidth Type Select a bandwidth type for the basic bandwidth plan.

    In this example, Premium is selected.

    Peak Bandwidth Select the bandwidth limit of the basic bandwidth plan.

    In this example, 2 Mbit/s is selected.

Step 2: Add an acceleration area

After you purchase a GA instance, you can add an acceleration area, specify the region where users are located, and then allocate bandwidth resources to the region.

  1. On the Instances page, find the GA instance and click its ID.
  2. Click the Acceleration Areas tab and then click Add Region on the Asia Pacific tab.
  3. In the Add Acceleration Area dialog box, set the following parameters and click OK.
    Parameter Description
    Regions Select the region where the users are located.

    In this example, China (Hong Kong) is selected.

    Bandwidth Specify a bandwidth value for the acceleration region.

    In this example, 2 Mbit/s is entered.

    Internet Protocol Select the IP address version used to access GA.

    In this example, IPv4 is selected.

    After you add the region, the system assigns an accelerated IP address to the region that is added to the GA instance. This accelerated IP address is used to accelerate data transfer from users in the specified region to the specified backend servers through GA. Accelerated IP address

Step 3: Add a listener and an endpoint group

A listener checks for connection requests and then distributes the requests to backend servers based on the specified protocol and ports. Each listener is associated with an endpoint group. You can associate an endpoint group with a listener by specifying the region to which you want to distribute network traffic. After you associate an endpoint group with a listener, traffic is distributed to the optimal endpoint in the associated endpoint group.

  1. On the instance details page, click the Listeners tab and then click Add Listener.
  2. On the Configure Listener & Protocol wizard page, set the following parameters and click Next.
    Listener
    Parameter Description
    Listener Name Enter a name for the listener.

    The name must be 2 to 128 characters in length, and can contain letters, digits, underscores (_), and hyphens (-). The name must start with a letter.

    Protocol Select the protocol of the listener.

    In this example, TCP is selected.

    Port Number Specify a listener port. The port is used to receive and forward requests to endpoints. Valid values: 1 to 65499.

    In this example, the value is set to 80.

    Client Affinity Specify whether to enable client affinity. If client affinity is enabled, requests from the same client are forwarded to the same endpoint when the client connects to a stateful application.

    In this example, Source IP Address is selected.

  3. On the Configure Endpoint Group wizard page, set the following parameters and click Next.
    Endpoint configuration
    Parameter Description
    Endpoint Group Name Enter a name for the endpoint group.

    The name must be 2 to 128 characters in length, and can contain letters, digits, underscores (_), and hyphens (-). The name must start with a letter.

    Region Select the region to which the endpoint group belongs, which is the region to which the backend servers belong.

    In this example, US (Silicon Valley) is selected.

    Backend Service Specify whether the web service is deployed on Alibaba Cloud.

    In this example, Off Alibaba Cloud is selected.

    Preserve Client IP Specify whether to preserve client IP addresses. After this feature is enabled, backend servers can retrieve client IP addresses.

    In this example, this feature is disabled.

    Endpoint Endpoints are backend servers that receive and handle client requests. Set the following parameters to configure an endpoint:
    • Backend Service Type: Select Custom Domain Name from the drop-down list.
    • Backend Service: Enter the domain name that you want to accelerate.
    • Weight: Enter a weight for the endpoint. Valid values: 0 to 255. GA routes network traffic to the endpoints based on their weights.
      Notice If you set the weight of an endpoint to 0, GA stops routing network traffic to the endpoint. Proceed with caution.
  4. On the Confirm wizard page, confirm the configurations of the listener and endpoint, and then click Submit.

Step 4: Add a CNAME record

To enable the acceleration service based on the CNAME assigned to your GA instance, you must configure a CNAME record to map your accelerated domain name to the CNAME.

  1. Log on to the Alibaba Cloud DNS console.
  2. On the Manage DNS page, find the domain name and click Configure in the Actions column to go to the DNS Settings page.
  3. Click Add Record, set the following parameters and click Confirm.
    Parameter Description
    Type Select CNAME from the drop-down list.
    Host Enter the prefix of the accelerated domain name.
    • If the accelerated domain name is www.aliyun.com, set the prefix to www.
    • If the accelerated domain name is aliyun.com, set the prefix to @.
    • If the accelerated domain name is *.aliyun.com, set the prefix to *.
    • If the accelerated domain name is mail.aliyun.com, set the prefix to mail.
    ISP Line Select Default from the drop-down list.
    Value Enter the CNAME value that is allocated to your GA instance.

    You can find the CNAME value on the Instances page.

    TTL Select 10 minute(s) from the drop-down list.
    Note
    • New CNAME records immediately take effect. If you modify the CNAME record, the record takes effect within 72 hours after it is modified.
    • After you add a CNAME record, it requires about 10 minutes for the system to update the status in the console. The message "You must add the CNAME record" may appear on the Domain Names page.

Step 5: Verify the acceleration performance

Note If you specify UDP as the protocol when you add a listener, you can verify the acceleration performance by using UDPing. For more information, see Test the acceleration performance a GA instance that uses a UDP listener.
  1. Open the CLI on an on-premises machine in the China (Hong Kong) region.
  2. Run the following command to query the network latency:
    curl -o /dev/null -s -w "time_connect: %{time_connect}\ntime_starttransfer: %{time_starttransfer}\ntime_total: %{time_total}\n" ""http[s]://<Domain name of the endpoint>[:<Port>]""
    In the command:
    • time_connect: the period of time that it takes to establish a TCP connection. Unit: seconds.
    • time_starttransfer: the start time of data transfer. The start time refers to the amount of time from when the client sends a request to the backend server to when the first byte is sent to the client. Unit: seconds.
    • time_total: the total connection time. The total connection time refers to the amount of time from when the client sends a request to when the client receives the last byte from the backend server. Unit: seconds.