If high latency and packet loss degrade your application's user experience, use Global Accelerator (GA) to route requests to the nearest access point on the Alibaba Cloud acceleration network and accelerate your application. This topic guides you through the process of using GA to accelerate access to a backend service at a specific IP address.
Use case
Consider this scenario: A company headquartered in Silicon Valley has deployed an enterprise application on a self-managed server. However, due to unstable internet connections, employees in the Hong Kong office experience high latency, jitter, and packet loss when accessing the application.
By configuring GA, traffic from the Hong Kong office enters the Alibaba Cloud acceleration network through a local access point. An intelligent routing system then directs the traffic to the application's endpoint in the US. This process improves access speed and the user experience for the Hong Kong employees.
This topic shows you how to configure a pay-as-you-go, standard GA instance. Note the following:
Pay-as-you-go GA instances use the Pay-by-data-transfer bandwidth billing method and do not need to be associated with a bandwidth plan. The fees for data transfer over the GA network are settled and billed by Cloud Data Transfer (CDT). For more information, see Data transfer fee.
The first time you use a pay-as-you-go GA instance, you must Activate the Service.
Step 1: Configure basic information about an instance
Log on to the GA console.
On the Instances page, click Create Standard Pay-as-you-go Instance.
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
To configure an acceleration area, specify the regions where the end users are located and allocate acceleration bandwidth to those regions.
On the Configure Acceleration Area page of the wizard, configure the following parameters, and click Next.
Parameter | Description |
Acceleration Area | Select one or more regions that you want to accelerate from the drop-down list. In this topic, the China (Hong Kong) region in the Asia-Pacific - China area is selected. |
Assign Bandwidth | |
Maximum Bandwidth | Set the bandwidth for the acceleration region. The value for each acceleration region ranges from 2 to 10,000 Mbps. This peak bandwidth serves a speed limit. The generated traffic fees are settled and billed by CDT. In this example, the default value 200 Mbps is used. Important If the peak bandwidth is set too low, traffic may be dropped due to throttling. Plan your peak bandwidth to match your business requirements. |
IP Protocol | Select the IP protocol for accessing the GA service. In this example, the default value IPv4 is used. |
ISP Line Type | Select the ISP line type for accessing the GA service. In this example, BGP (Multi-ISP) is selected. |
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 following parameters, and click Next.
Parameter | Description |
Listener Name | Enter a name for the listener. |
Routing Type | Select a routing type. In this topic, Intelligent Routing is selected. |
Protocol | Select a protocol for the listener. In this topic, TCP is selected. |
Port | Specify the listener port that is used to receive requests and forward them to endpoints. Valid values: 1 To 65499. In this topic, port 80 is used. |
Client Affinity | Select whether to maintain client affinity. When enabled, client affinity directs all requests from the same client to the same endpoint. In this example, Source IP is selected. |
Step 4: Configure an endpoint group and endpoints
On the Configure an endpoint group page, configure the endpoint group and endpoints, and click Next.
Parameter
Description
Region
Select the region where the endpoint group belongs.
In this topic, US (Silicon Valley) is selected.
Endpoint Configuration
Endpoints are the destination hosts that process client requests. Configure endpoints based on the following information:
Backend Service Type: Select Custom Public IP Address.
Backend Service: Enter the IP address of the backend service that you want to accelerate.
Weight: Enter the weight of the endpoint. Valid values: 0 to 255. GA routes traffic to endpoints based on the weights that you configure. In this topic, the default value 255 is used.
WarningIf the weight of an endpoint is set to 0, Global Accelerator stops distributing traffic to that endpoint. Proceed with caution.
Preserve Client IP
Select whether to preserve client source IP addresses.
When the listener protocol is TCP and you enable this feature, you must configure the backend server to retrieve client source IP addresses. The adaptation method varies by backend service type. For more information, see Preserve client IP addresses.
In this example, client source IP addresses are not preserved.
Traffic Distribution Ratio
Configure the traffic ratio to different endpoint groups.
The valid values are 0 to 100.
In this example, the default value 100% is used.
Health Check
Enable or disable health checks.
When enabled, GA uses health checks to monitor the status of your endpoints. For more information about health checks, see Enable and manage health checks.
In this example, health checks are disabled by default.
On the Configuration Review wizard page, confirm the information and click Submit.
NoteIt takes 3 to 5 minutes to create a GA instance.
(Optional) After the task is complete, click Go to Instance Details in the task details list. On the instance details page, view the instance configurations on the Instance Information, Listeners, and Acceleration Areas tabs.
Step 5: Test the acceleration effect
If you specify UDP as the protocol when you add a listener to Global Accelerator, you can verify the acceleration performance of Global Accelerator by using UDPing. For more information, see Verify the acceleration performance of a UDP listener.
On a computer in the access region, open a command-line window. In this example, the region is China (Hong Kong.
Run the following command to check the latency.
curl -o /dev/null -s -w "time_connect: %{time_connect}\ntime_starttransfer: %{time_starttransfer}\ntime_total: %{time_total}\n" "http[s]://<accelerated IP address>[:<port>]"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.
After testing, the total connection time from clients in China (Hong Kong) to the backend service in US (Silicon Valley) is reduced, indicating lower access latency.
Figure 1. Latency before acceleration with the backend service IP address
Figure 2. Latency after acceleration with the accelerated IP address
NoteThe actual acceleration performance of GA depends on your business tests.
(Optional) Step 6: Configure a CNAME record
If you have a domain name, we recommend using it for your enterprise application. Assume your domain name is example.com. You can perform the following actions:
Add a CNAME record. In this example, a CNAME record is added to map the domain name
www.example.comto the CNAME assigned to the GA instance.Add an A record. In this example, an A record is added to map the domain name
www.example.comto the IP address of the backend service in US (Silicon Valley). The resolution line is set to North America_United States.
By default, Alibaba Cloud DNS is the Free Edition. You must upgrade to the Enterprise Ultimate Edition to intelligently return resolution results for end-users in different regions. For instructions on how to upgrade, see Renewal. If you use a different DNS provider, consult its documentation.
On the Public Zone page, find your domain name and click Settings in the Actions column.
NoteFor non-Alibaba Cloud domains, you must add it to Alibaba Cloud DNS before configuring a DNS record. For more information, see Add a domain name. Skip this step if you are using Alibabab Cloud DNS.
On the Settings page, click Add Record, add CNAME and A records with the following configurations, and click OK.
Parameter
Description
Record Type
Select CNAME.
Select A.
Hostname
Enter the prefix of your domain name.
In this example, enter www.
Query Source
Keep the default value.
Select Region, Outside Chinese Mainland, North America, and United States in sequence.
TTL
This cache time for the DNS record on the DNS server. A smaller value results in faster propagation of record changes.
In this example, the default value of 10 minutes is used.
Record Value
Enter the CNAME assigned to the Global Accelerator instance.
On the Instances page, you can view the CNAME assigned to the Global Accelerator instance.
Enter the IP address of the backend service in US (Silicon Valley).
With these configuration, company employees can access the enterprise application through the domain www.example.com. Employees in the United States access the backend service in Silicon Valley, while users in Hong Kong and other regions will be routed through GA for accelerated access.
More information
You can also use the quick configuration template provided by Resource Orchestration Service (ROS) to accelerate access from clients in Hong Kong to the backend service in Silicon Valley by IP address. To do this, go to the quick configuration template and follow the on-screen instructions for a faster setup.