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This article mainly introduces "the introduction of the operation principle and component architecture of Serverless". In the daily operation, I believe that many people have doubts about the introduction of the operation principle and component architecture of Serverless. The editor consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts of "introduction to the operation principle and component architecture of Serverless". Next, please follow the editor to study!

This article focuses on some problems that developers often encounter when using Serverless, and how to solve them.

Over the past year, we have communicated with a large number of Serverless users both online and offline to understand their business scenarios, views and experiences with Serverless.

Most users think that Serverless will be the inevitable trend in the next phase of cloud computing, but not now. Why? Because although the cloud functions that make up the Serverless architecture boast the ability to automatically expand and shrink, the bad development experience, the dreaded cold start, the difficult problems of transforming the original business, and so on, all reduce the confidence of users.

Therefore, although many users recognize the value of Serverless, they still think that it is difficult to carry core business.

To address these key issues, Tencent Cloud released Serverless 2.0 in June this year, comprehensively upgrading the product form, system scheduling and developer tools. In order to make it easier for you to understand, we will start from the operating principle of the cloud function as a starting point to explain the causes of the problem and how to deal with it.

First of all, let's take a look at the differences between cloud functions, or FaaS, IaaS and PaaS.

As shown in the figure below, FaaS not only provides users with standard Runtime, but also helps users manage the scheduling of requests at the application layer. Developers only need to focus on the development of core business logic and write code according to the granularity of the function. The maintenance of resources related to the underlying hardware will be handed over to more professional cloud vendors.

Therefore, for users, they can devote more energy and time to the business. On the other hand, both IaaS and PasS require users to operate and maintain the CVM or container cluster and build the running environment required for the business.

Secondly, let's take a look at how cloud functions constitute the Serverless architecture, and how cloud functions help users do resource management and request scheduling.

Here, we will also answer questions such as cold startup of cloud functions and reducing the complexity of core business migration.

As shown in the figure below, developers can use Web IDE or local IDE to complete code development, and then package and deploy the code and its related dependencies to the cloud function platform through plug-ins, tools and other means. Users can choose to deploy as a function or a service.

In the code, users need to implement their own business logic, such as accessing databases, object storage, message queues, third-party service interfaces, and so on. Computing logic and back-end services together constitute the so-called Serverless application architecture. According to the request method provided by the platform, the end user triggers the business code deployed on the cloud function platform, such as sending http request, and the platform will pull up the corresponding computing resources and run the user code according to the number of user requests.

Here, we need to focus on the difference between function form and service form, because the form of service can greatly reduce the cost of complex business migration.

The service form supports the direct deployment of core businesses developed based on the framework, such as Node.js 's express, koa and other frameworks, without having to split into functions for the application of Serverless. The platform will help users start the service process and port listening, and the service form will not limit the actual running time of the business.

Both the function form and the service form can expand and shrink automatically when they receive the user's request.

The function form allocates a running instance for each request of the user, so the execution experience of all requests is the same. When there is no request, there is no instance running on the platform, so you can make on-demand requests, but this can also lead to so-called cold start-- that is, when the user's first request enters the platform, the platform temporarily pulls up resources. and this process takes a certain amount of time. To eliminate cold starts, the cloud function platform initializes a number of instances of different specifications in the resource pool in advance. When users have a request to enter, they can quickly apply for an instance from the resource pool and directly mount the user's code to run. As a result, the resource application time is reduced. At the same time, for the function form, the platform will predict based on the historical concurrent data to help users reserve a certain number of instances, which will be pre-assigned to the user's account and loaded with the user's code, which not only eliminates the cold start directly, but also increases the probability of instance reuse.

On the other hand, the service form can reserve at least one resident instance for the user, and deliver all the user's requests to the first instance, and automatically expand and shrink dynamically according to the usage of the instance.

The function form is more suitable for new projects, which can be agile and iterative, and the business is developed according to the granularity of the function. You can not only easily achieve the linkage of multiple products on the cloud, but also enjoy the experience of high concurrency and consistent performance of functions. The service form is more suitable for the migration of existing projects, heavy complex businesses, and businesses that need to run for a long time.

Finally, I will talk about the component architecture of Serverless 2.0.

As shown in the following figure, although users only need to focus on the green part of the business-related code implementation, the platform also needs to provide powerful developer tools to ensure the development and use experience. For example, Serverless local development tools and VS Code plug-ins launched by Cloud function, and Web IDE and DevOps platforms jointly launched with CODING can greatly improve the efficiency of development and deployment, and achieve the capabilities of development, local debugging, linkage cloud debugging, local deployment, version release and so on.

At the same time, SCF also improves the supporting monitoring and alarm mechanism, providing multi-dimensional monitoring and alarm capabilities, such as number of calls, memory usage, concurrent use, timeout, code errors and so on. These infrastructure, resource management, security, disaster recovery and other capabilities are the necessary basic capabilities of the cloud function platform, as well as the core competencies that developers care about.

Serverless is not only computing, but also needs to constantly improve the surrounding ecology.

With the increase of the number of users, Serverless will inevitably face more challenges-how to help users organize and manage the code, how to solve the business demands with state, how to manage the number of database connections, how to achieve application-level deployment, and so on. We are also constantly exploring and optimizing the user experience, planning to provide features such as Serverless DB, performance monitoring, log analysis, Serverless framework, function orchestration, high-performance calls, and so on.

At this point, the study on the "introduction to the operation principle and component architecture of Serverless" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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