CDN:What is EdgeRoutine?

Instructions for activation

EdgeRoutine is in beta release and available only to selected users. If the daily peak bandwidth of your Alibaba Cloud CDN service exceeds 500 Mbit/s, you can submit a ticket to activate EdgeRoutine. We apologize for any inconvenience caused to you. We recommend that you pay attention to the official website.

Benefits

• Global deployment, near-site scheduling, and ultra-low latency: Compared with common cloud computing services, such as Function Compute and Elastic Compute Service (ECS), EdgeRoutine does not need to be deployed in a specific region. EdgeRoutine runs on POPs around the world. Client requests are automatically scheduled to the nearest POPs, which immediately run your code and process client requests. EdgeRoutine can significantly reduce the server response time, which helps you deliver low-latency services to your users.

• Automatic scale-out and pay-as-you-go billing: Alibaba Cloud has constructed an edge network that consists of more than 3,200 POPs around the world. These POPs provide unparalleled scalability. If the number of client requests in a region surges, these requests are automatically scheduled to the nearest POPs that have sufficient computing resources. You are charged for EdgeRoutine based on the number of calls that are made to the service.

• Easy-to-use serverless environment: EdgeRoutine allows you to focus on your business logic without having to manage underlying resources, such as the CPU, memory, network, and operating system. You can upload your code by using the console or API to deploy applications. Serverless development can effectively cut your development and O&M costs.

Principles

• Scenarios in which EdgeRoutine is not used: 1. Clients initiate requests to the gateways of the POPs. → 2. The POPs search for the requested content in the cache. If a request is a cache hit, the requested content is returned to the client. → 3. If a request is a cache miss, the request is redirected to the origin server.

• Scenarios in which EdgeRoutine is used: 1. Clients initiate requests to the gateways of the POPs. → 4. The requests are managed by EdgeRoutine, and the relevant JavaScript code is triggered. → Fetch requests are sent to the cache and origin server (No. 5 or No. 3), or to other publicly-accessible services (No. 6).

  Note

  In the preceding figure, EdgeRoutine is executed behind the gateway. In this case, the configurations of Alibaba Cloud CDN-accelerated domain names that are configured in the console, such as HTTPS configurations, access control, performance optimization, and cache settings, will continue to take effect.

Basic concepts

• Routine: EdgeRoutine is a JavaScript code runtime environment that runs on Alibaba Cloud POPs. You can upload and run JavaScript code in EdgeRoutine. You need to create a routine before you can use EdgeRoutine. A routine consists of configurations and the JavaScript code script that you upload. The configurations specify information about the routine, such as the name, description, CPU and memory caps, and domain name whitelist.

  

• Version: Routines support version management. During the development of a routine, JavaScript code is constantly modified and updated. After you complete testing for a stage, you can create a code version by taking a snapshot of the current state of the code. When you publish a routine, you need to select a code version. The system allows you to select earlier versions and manage historical code. Each version has a version number, which is automatically generated by the system.

  

• Environment: EdgeRoutine provides the staging environment, production environment, and canary environment.

  

  • Staging environment: A staging environment is an independent POP that is used to test code. The staging environment simulates the production environment but is isolated from the production environment. You can modify the routine configuration or code in the staging environment. This does not affect the production environment. You can access the staging environment only after you add the IP address that is provided on the page to your hosts file.

  • Production environment: The production environment, also known as the deployment environment, consists of a large number of POPs that are distributed around the world. After you test your code in the staging environment, you can deploy the code to the production environment. The preceding figure is provided for reference only. EdgeRoutine automatically adds or removes POPs based on your request volume. The POP distribution may vary according to actual scenarios.

  • Canary environment: This environment allows you to gradually expand the scope of your deployment. It is risky to deploy code or configuration changes directly to the production environment. If errors exist in your code or configurations, your users may be affected. If your business is large-scale or you want to control risks when you make code or configuration changes, we recommend that you use the canary environment to manage the deployment scope. The canary environment is complex. We recommend that you understand the basics of the environment before you use the canary environment. For more information, see Canary environment (optional).

• Domain name: After you create a routine and deploy code, you need to use a domain name as the portal of the routine that clients can access. EdgeRoutine supports only Alibaba Cloud CDN-accelerated domain names as portals. You can associate EdgeRoutine with domain names in the Alibaba Cloud CDN console.

  

• POP: POPs are used by Alibaba Cloud CDN for content delivery. Client requests are scheduled to the nearest POPs.

Limits