Global Accelerator:Accelerate access to backend services of a specific domain name

Scenario

This topic uses the following scenario. A company is headquartered in the US (Silicon Valley). The company has deployed a web service on a self-managed server. The web service is accessible through the domain name www.example.com on port 80. Because of unstable cross-border networks, employees in the China (Shenzhen) office often experience issues such as latency, jitter, and packet loss when they access the web service on the server in the US.

You can configure Global Accelerator to direct traffic from the China (Shenzhen) office to the server in the US (Silicon Valley). The traffic enters the Alibaba Cloud acceleration network from an access point in China (Shenzhen) through an accelerated IP address. Then, smart routing forwards the client requests to the endpoint. This improves access speed and the user experience for the China (Shenzhen) office.

Prerequisites

Step 1: Configure basic information about an instance

1. Log on to the GA console.

2. On the Instances page, click Create Standard Pay-as-you-go Instance.

3. In the Basic Instance Configuration step, configure the parameters based on the following table and click Next.

   Parameter	Description
   GA Instance Name	Enter a name for the GA instance.
   Instance Billing Method	Pay-As-You-Go is selected by default. You are charged instance fees, Capacity Unit (CU) fees, and data transfer fees for pay-as-you-go standard Global Accelerator instances. For more information about instance fees and CU fees, see Billing of pay-as-you-go GA instances. For more information about data transfer fees, see Pay-by-data-transfer.
   Resource Group	Select the resource group to which the standard Global Accelerator instance belongs. The resource group must be created by the current Alibaba Cloud account in Resource Management. For more information, see Create a resource group.

Step 2: Configure an acceleration area

Configure an acceleration area for the Global Accelerator instance. You must specify the regions where users are located and allocate bandwidth for acceleration.

On the Configure Acceleration Areas page, specify an acceleration area and click Next.

Step 3: Configure a listener

A listener listens for connection requests and distributes the requests to endpoints based on the port and the protocol that you specify. 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, network traffic is distributed to the optimal endpoint in the endpoint group.

On the Configure listeners page, configure the listener and click Next.

This section describes only the parameters that are relevant to this example. For other parameters, you can use the default values or change them as needed. For more information, see other listener parameters.

Step 4: Configure an endpoint group and endpoints

1. On the Configure an endpoint group page, configure the endpoint group and its endpoints.

   This section describes only the parameters that are relevant to this example. For other parameters, you can use the default values or change them as needed. For more information, see other endpoint group parameters.

   Configuration	Description
   Region	Select the region where the endpoint group is deployed. In this example, US (Silicon Valley) is selected.
   Endpoint Configuration	Endpoints are the destination hosts that process client requests. Configure the endpoints based on the following information: Backend Service Type: Select Custom Domain Name. Backend Service: Enter the domain name of the backend service to accelerate. For example, enter <span data-tag="ph" id="660885e040gyk"><code code-type="xCode" data-init-id="c8ca1375873eg" data-tag="code" id="8c084dcb00jj3">www.example.com. Weight: Enter a weight for the endpoint. The weight can be an integer from 0 to 255. Global Accelerator routes traffic to endpoints based on the weights that you specify. In this example, the default value 255 is used. Warning If you set the weight of an endpoint to 0, Global Accelerator stops distributing network traffic to the endpoint. Proceed with caution.

2. Read the Compliance Commitments Regarding Cross-border Data Transfers, select Agree to the Preceding Compliance Agreement, and click Next.

   In this scenario, the configuration involves acceleration from China (Shenzhen) to the US (Silicon Valley). You must agree to the Compliance Commitments Regarding Cross-border Data Transfers to enable this feature.

   After an instance is created, the Transmission Network Type is set to BGP (Multi-ISP) Pro by default. This enables network acceleration between the Chinese mainland and other regions, such as Hong Kong (China), Macao (China), and Taiwan (China), without requiring additional configuration. For more information, see Data transfer billing.

3. On the Configuration Review wizard page, confirm the information and click Submit.

   Note

   It takes 3 to 5 minutes to create a GA instance.

4. Optional: After the instance is created, click Go to Instance Details below the task list. On the instance details page, you can click the Instance Information, Listeners, or Acceleration Areas tabs to view the instance configuration.

Step 5: Configure a CNAME record

To enable the acceleration service, you must map your accelerated domain name to the canonical name (CNAME) that is assigned to the Global Accelerator instance. You can perform the following operations:

• Change the default DNS record of the existing A record to a region-specific DNS record. In this example, the DNS record is changed to North America_United States to handle requests from outside the Chinese mainland.

• Add a CNAME record. In this example, a CNAME record is added to map the domain name www.example.com to the CNAME assigned to the Global Accelerator instance.

Note

By default, the Free Edition of Alibaba Cloud DNS is used. You must upgrade Alibaba Cloud DNS to the Standard or Ultimate Edition to return intelligent DNS query results to end users in different regions. For more information about how to upgrade, see Renewal.

1. On the Authoritative DNS Resolution page, find the domain name that you want to use and click DNS Settings in the Actions column.

   Note

   For a domain name that is not registered with Alibaba Cloud, you must add the domain name to the Alibaba Cloud DNS console before you can configure DNS records.

2. On the DNS Settings page, modify the existing A record and click the OK button.

   1. Find the A record and click Modify.

   2. In the Mondify DNS Record panel, select Outside Chinese Mainland, North America, and United States from the DNS Request Source drop-down list.

3. On the DNS Settings page, click Add DNS Record, configure the CNAME record parameters, and then click OK.

   Configuration	Description
   Record Type	Select CNAME.
   Hostname	Enter the prefix of the accelerated domain name. In this example, enter www.
   DNS Request Source	Use the default value.
   TTL	The period of time that a DNS record is cached on a DNS server. A smaller value indicates that the record modifications take effect faster. In this example, the default value of 10 minutes is used.
   Record Value	Enter the CNAME assigned to the Global Accelerator instance. You can view the CNAME assigned to the Global Accelerator instance on the Instances page.

Step 6: Test the acceleration performance

This topic uses Alibaba Cloud Linux 3 as an example. Test commands vary based on the operating system. For more information about the test commands, see the user guide for your operating system.

1. Open the command-line interface (CLI) on a computer in the acceleration area. In this example, the acceleration area is China (Shenzhen).

2. Run the following command to check whether the CNAME record has taken effect:

   ping <Accelerated domain name>

   If the resolved CNAME matches the CNAME of the Global Accelerator instance, the CNAME record has taken effect.

3. Run the following command to view the packet latency:

   curl -o /dev/null -s -w "time_connect: %{time_connect}\ntime_starttransfer: %{time_starttransfer}\ntime_total: %{time_total}\n" "http[s]://<Accelerated domain name>"

   Take note of the following parameters:

   • time_connect: The period of time that is required 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 period of time from the time when the client sends a request to the time when the client receives the last byte from the backend server. Unit: seconds.

   The test results show that after Global Accelerator is used, the total connection time from the client in China (Shenzhen) to the web service in the US (Silicon Valley) is reduced. This means that latency is reduced for the client in China (Shenzhen) when accessing the web service in the US (Silicon Valley).

   Figure 1. Access latency before acceleration

   Figure 2. Access latency after acceleration

   Note

   The acceleration performance of Global Accelerator is subject to the results of your actual business tests.