Accelerate ALB backend applications using Global Accelerator - Global Accelerator

When your Application Load Balancer (ALB)-hosted service is accessed by users across multiple regions globally, poor public network quality can cause high latency, jitter, and packet loss, degrading the end user experience. Use Alibaba Cloud Global Accelerator (GA) to accelerate your application. End user requests enter Alibaba Cloud at the nearest point of presence and travel over Alibaba Cloud’s private accelerated network to reach your application servers.

Scenario example

A company deploys a highly available service using ALB in the China (Hangzhou) region and plans to serve end users in multiple global regions. Due to suboptimal cross-region public network quality, some end users experience high network latency, which affects their access experience.

To solve this issue, the company deploys Global Accelerator (GA). This enables end user requests to enter Alibaba Cloud at the nearest point of presence and travel over an accelerated network, significantly improving the user access experience.

Prerequisites

Have created and managed an ALB instance.
Have created and managed a server group for the ALB instance.
Have added ECS01 and ECS02 instances to the ALB server group and deployed application services on both ECS01 and ECS02.

This topic uses Alibaba Cloud Linux 3 as the operating system and configures a backend HTTP service on port 80 using Nginx.
Example commands to deploy the test service on ECS
Commands for ECS01:
```
yum install -y nginx
systemctl start nginx.service
cd /usr/share/nginx/html/
echo "Hello World ! This is ECS01." > index.html
```
Commands for ECS02:
```
yum install -y nginx
systemctl start nginx.service
cd /usr/share/nginx/html/
echo "Hello World ! This is ECS02." > index.html
```
Have registered a custom domain name, completed ICP filing, and configured a DNS CNAME record pointing to the ALB instance.
Have created an HTTP listener or an HTTPS listener for the ALB instance. If using an HTTPS listener, create and request a certificate or upload a third-party certificate to SSL Certificate Service and bind it to your custom domain name.

Procedure

Configure GA to accelerate your ALB backend application in one of two ways:

Add ALB as a backend service in the GA console for customizable configuration.
Use the one-click GA configuration in the ALB console for quick setup.

Add ALB as a backend service in the GA console

Step 1: Configure basic instance information

This topic uses a pay-as-you-go medium GA instance as an example.

In the Global Accelerator console, go to the Standard Instance > Instances page and click Create Standard Pay-as-you-go Instance.
On the Basic Instance Configuration wizard page, configure basic settings and click Next.

Enter a Global Accelerator instance name and confirm that Instance billing method is set to Pay-as-you-go.

Step 2: Configure acceleration areas

On the Configure Acceleration Area wizard page, add acceleration regions, allocate bandwidth, and click Next.

This example uses the US (Silicon Valley) region. Set Acceleration area to US (Silicon Valley). Set ISP Line Type to BGP (Multi-ISP). Keep other acceleration area parameters at default values or adjust as needed. In this example, set peak bandwidth to 200 Mbps and IP protocol version to IPv4.

Step 3: Configure listeners

On the Configure Listener wizard page, set the forwarding protocol and port, then click Next.

In this scenario, set Protocol to HTTP and Port to 80. Keep other listener parameters at default values or adjust as needed.

Note

UDP listeners do not support ALB-type backend services.

Step 4: Configure endpoint groups and endpoints

On the Configure an Endpoint Group wizard page, configure the backend service and click Next.

In this scenario, set Region to China (Hangzhou). Set Backend Service Type to ALB. Select your target ALB instance for Backend Service. Read and select Compliance Commitments Regarding Cross-border Data Transfers. Keep other endpoint group parameters at default values or adjust as needed.
On the Configuration Review wizard page, confirm your GA configuration and click Submit.

Step 5: Configure CNAME

Point your custom domain’s DNS record to the CNAME assigned by the GA instance. This routes service traffic through GA for accelerated access.

If you already have a CNAME record pointing to ALB, first create a CNAME record for GA targeting users in the US for testing. After successful testing, gradually expand to other regions or replace the ALB CNAME with the GA CNAME.

On the Domain Name Resolution page, find your custom domain and click Configure DNS in the Actions column.

Note
For domains registered outside Alibaba Cloud, first add the domain to the Cloud DNS console before configuring DNS records.
On the DNS configuration page, click Add Record, configure the CNAME record, and click OK.

In this scenario, set Record Type to CNAME. Set Hostname to www. Set DNS Request Source to the US in North America. Set Value to the GA instance’s CNAME. Keep other DNS record parameters at default values or adjust as needed.

Step 6: Verify acceleration performance

This test uses a public ALB instance with backend servers in China (Hangzhou) and clients accessing from the US acceleration area.

Test network latency after acceleration:
1. Access http://<custom domain> in a browser to verify normal backend access. Refresh the browser multiple times to switch between ECS01 and ECS02.
2. Run curl -o /dev/null -s -w "time_connect: %{time_connect}\ntime_starttransfer: %{time_starttransfer}\ntime_total: %{time_total}\n" "http[s]://<custom domain>" to check packet latency after acceleration.
  After acceleration, the output looks like this:
```
[root@iZxxx ~]# curl -o /dev/null -s -w "time_connect: %{time_connect}\ntime_starttransfer: %{time_starttransfer}\ntime_total: %{time_total}\n" "http://xxx.com"
time_connect: 0.008
time_starttransfer: 0.207
time_total: 0.207
```
Test network latency before acceleration:
1. Access http://<custom domain> in a browser to verify normal backend access. Refresh the browser multiple times to switch between ECS01 and ECS02.
2. Run curl -o /dev/null -s -w "time_connect: %{time_connect}\ntime_starttransfer: %{time_starttransfer}\ntime_total: %{time_total}\n" "http[s]://<custom domain>" to check packet latency before acceleration.
  Before acceleration, the output looks like this:
```
[root@iZxxx ~]# curl -o /dev/null -s -w "time_connect: %{time_connect}\ntime_starttransfer: %{time_starttransfer}\ntime_total: %{time_total}\n" "http://xxx.com"
time_connect: 0.017
time_starttransfer: 0.427
time_total: 0.427
```

Compare acceleration results. Parameter definitions:

time_connect: Connection time in seconds—from start until TCP connection establishment completes.
time_starttransfer: Time to first byte in seconds—from client request until the backend server sends the first response byte.
time_total: Total connection time in seconds—from client request until the backend server completes the session response.

Parameter	After acceleration (seconds)	Before acceleration (seconds)	Acceleration Data Reference (Seconds)	Improvement (%)
time_connect	0.008	0.017	Increase by 0.009	52.9% faster
time_starttransfer	0.207	0.427	Improvement of 0.220	51.5% faster
time_total	0.207	0.427	Improved by 0.220	51.5% faster

Note

The example and data in this topic are for reference only. Actual acceleration performance depends on your specific business tests.

You can also use the or the One-time Network Probe tool to test acceleration performance before and after GA configuration. Check response times to understand data latency.

Configure GA with one click in the ALB console

ALB integrates GA services. You can enable GA acceleration directly in the ALB console to simplify setup.

Limits

Each ALB instance can be associated with only one GA instance for acceleration.
The following ALB instances do not support application acceleration:
- The ALB instance has no listeners configured.
- The ALB instance or its listener is being upgraded or downgraded.
- The ALB instance has a QUIC listener configured.
- The ALB instance has an HTTPS listener with any of the following configurations:
  - Mutual authentication is enabled.
  - A custom TLS security policy is used.
  - Extended certificates are configured.
- The ALB instance has a listener associated with a backend server group that uses the gRPC protocol.
- The ALB instance is deployed in a region where GA is not available. For details on GA-supported regions, see Acceleration regions and supported areas.
- The public IP address range of the GA instance’s endpoint is either in the ACL blacklist of the public ALB listener or conflicts with addresses in the ACL whitelist. For information on how to obtain the public IP address of a GA instance endpoint, see How to obtain the public IP address of a Global Accelerator instance endpoint?

Step 1: Enable application acceleration for your ALB instance

Log on to the Application Load Balancer (ALB) console.
In the top menu bar, select the region where your instance is deployed.
On the Instances page, find your target instance and click its instance ID.
On the Integrated Services tab, click Create GA.
1. Activate GA: If you have never used GA, read the Global Accelerator Service Agreement and check the box to activate the service.
2. Acceleration Area: Acceleration regions are the geographic areas where you want to accelerate access. Choose the region where your clients are located or the nearest region. Each acceleration region includes one or more Alibaba Cloud regions.
  Note
  - If your acceleration region includes the Chinese mainland or your backend servers are deployed in the Chinese mainland, you must complete ICP filing for your custom domain name.
  - If your acceleration region and origin server region involve cross-border access, read the Compliance Commitments Regarding Cross-border Data Transfers and check the box to agree. Premium bandwidth for cross-border acceleration is enabled by default.
After completing the configuration, click OK.

Important
The first time you enable acceleration, all listener configurations from your ALB instance are synchronized to GA. Subsequent changes to ALB listeners are not automatically synchronized. You must manually update them in the GA console.

Step 2: Configure CNAME resolution

Configure DNS to point your custom domain to the GA CNAME. This routes service traffic through GA for accelerated access.

After enabling GA acceleration for your ALB instance, the Integrated Services page displays the created GA instance details, including the DNS name (GA CNAME).

On the Domain Name Resolution page, find your custom domain and click Configure DNS in the Actions column.

Note
For domains registered outside Alibaba Cloud, first add the domain to the Cloud DNS console before configuring DNS records.
On the DNS configuration page, click Add Record, configure the CNAME record, and click OK.

In this scenario, set Record Type to CNAME. Set Hostname to www. Set DNS Request Source to the US in North America. Set Value to the GA instance’s CNAME. Keep other DNS record parameters at default values or adjust as needed.

Step 3: Verify acceleration performance

This test uses a public ALB instance with backend servers in China (Hangzhou) and clients accessing from the US acceleration area.

Test network latency after acceleration:
1. Access http://<custom domain> in a browser to verify normal backend access. Refresh the browser multiple times to switch between ECS01 and ECS02.
2. Run curl -o /dev/null -s -w "time_connect: %{time_connect}\ntime_starttransfer: %{time_starttransfer}\ntime_total: %{time_total}\n" "http[s]://<custom domain>" to check packet latency after acceleration.
  After acceleration, the output looks like this:
```
[root@iZxxx ~]# curl -o /dev/null -s -w "time_connect: %{time_connect}\ntime_starttransfer: %{time_starttransfer}\ntime_total: %{time_total}\n" "http://xxx.com"
time_connect: 0.008
time_starttransfer: 0.207
time_total: 0.207
```
Test network latency before acceleration:
1. Access http://<custom domain> in a browser to verify normal backend access. Refresh the browser multiple times to switch between ECS01 and ECS02.
2. Run curl -o /dev/null -s -w "time_connect: %{time_connect}\ntime_starttransfer: %{time_starttransfer}\ntime_total: %{time_total}\n" "http[s]://<custom domain>" to check packet latency before acceleration.
  Before acceleration, the output looks like this:
```
[root@iZxxx ~]# curl -o /dev/null -s -w "time_connect: %{time_connect}\ntime_starttransfer: %{time_starttransfer}\ntime_total: %{time_total}\n" "http://xxx.com"
time_connect: 0.017
time_starttransfer: 0.427
time_total: 0.427
```

Compare acceleration results. Parameter definitions:

time_connect: Connection time in seconds—from start until TCP connection establishment completes.
time_starttransfer: Time to first byte in seconds—from client request until the backend server sends the first response byte.
time_total: Total connection time in seconds—from client request until the backend server completes the session response.

Parameter	After acceleration (seconds)	Before acceleration (seconds)	Acceleration Data Reference (Seconds)	Improvement (%)
time_connect	0.008	0.017	Increase by 0.009	52.9% faster
time_starttransfer	0.207	0.427	Improvement of 0.220	51.5% faster
time_total	0.207	0.427	Improved by 0.220	51.5% faster

Note

The example and data in this topic are for reference only. Actual acceleration performance depends on your specific business tests.

You can also use the or the One-time Network Probe tool to test acceleration performance before and after GA configuration. Check response times to understand data latency.

FAQ

What type of GA instance is created?

A pay-as-you-go standard GA instance.

How does enabling application acceleration affect billing?

Enabling application acceleration adds GA-related charges, including instance fees, CU fees, and traffic fees. For details, see Billing for pay-as-you-go Global Accelerator instances.

Why isn’t my updated ALB listener accelerated?

When you first enable GA integration, all ALB listener configurations are synchronized to GA. Subsequent changes to ALB listeners are not automatically synchronized. You must manually update them in the GA console.

Why did my ALB access control policy stop working after acceleration?

After GA acceleration, end users access your service through the GA DNS name. Therefore, the ALB access control policy no longer applies.

To enforce similar IP-based access control, configure an access control policy in GA. For more information, see GA access control.

References

ALB billing overview: Learn about ALB billing methods and components.
GA billing overview: Learn about GA billing methods and components.
Cross-border acceleration configuration selection: For cross-border scenarios, premium bandwidth cross-region acceleration is used by default. For higher network quality, use leased line cross-region acceleration.