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Editor to share with you what Kubernetes and Docker are, I believe most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's go to know it!

What is Docker?

Although we have been talking about containers and discussing the construction of container-based infrastructure, we do not understand the real connotation of container technology and do not know how this technology solves enterprise business problems. In the author's opinion, container technology is actually "server management technology". Why do you say that? Because the most fundamental reason for the birth of container technology is the challenge of server management, especially the server based on Linux system.

Of course, it's not that Linux servers are complex, but because Linux is the only server system related to Internet services today, we need to consider how to run servers based on Internet services and make sure they are not attacked. However, sometimes, too much server support is a waste of resources, so we put forward the concept of micro-service. Micro-service is a new software architecture, which divides a large single application and service into dozens of micro-services.

Aiming at the concept of microservices, Linux launched a technology called "cgroups" in 2006. Cgroups, which stands for controlgroups, is a mechanism provided by the Linux kernel to limit, record, and isolate physical resources (such as cpu,memory,IO, etc.) used by process groups (processgroups). Cgroups provides a basic guarantee for container virtualization and is the cornerstone of building a series of virtualization management tools such as Docker. However, if you are not familiar with Linux kernel technology, it is not particularly easy to use cgroups, which is one of the fundamental reasons why Cgroups is not known.

The emergence of Docker provides a more convenient Linux server management tool than cgroups. Docker is so easy to use that many people don't realize that they are using Linux kernel technology. With Docker, developers can run multiple applications on one server, all applications completely use the sandbox mechanism, there will not be any interface between each other, this isolation mechanism greatly ensures the security of each application. Among them, Docker Swarm is one of the core tools of Docker, which can combine different servers into a cluster. This clustering effect begins to work when multiple servers are managed.

So when we talk about containers, especially Docker, we're basically talking about Linux kernel technology.

What is Kubernetes?

So, what is Kubernetes? Why do we need it? To better understand this, you can assume an application scenario where there is a data center with thousands of servers, and operators maintain not just one micro service, but thousands of them. at this time, we must rely on a large operating platform to manage. Therefore, Kubernetes has fertile ground for growth.

Kubernetes is an open source container orchestration engine for Google, which supports automated deployment, large-scale scalability, and application containerization management. When deploying an application in a production environment, multiple instances of the application are usually deployed to load balance application requests. In Kubernetes, we can create multiple containers and run an application instance in each container, and then manage, discover and access this group of application instances through the built-in load balancing policy, and these details do not need to be manually configured and processed by operation and maintenance personnel.

Why use Docker instead of Kubernetes?

Why should we use Docker instead of Kubernetes. As mentioned earlier, when we talk about container technology, the focus is on Linux kernel technology. If you want to use containers in your project, you should have some experience with Linux. Docker container integrates cgroups technology, provides a more ideal tool set, and realizes the isolation and control of container resources.

Kubernetes technology is not suitable for small companies, let alone the operation of a single web project. Although it can be used in theory, it will be "overqualified", just like we don't go on holiday in a rocket. Of course, we're not trying to crack down on Kubernetes, it's a great and free technology, but not all technologies are suitable for us. We have to ask ourselves whether this clock technology is really needed. Kubernetes is more suitable for an environment with a large architecture and growing applications, such as Google, Amazon and Microsoft.

In addition, it is easier to build a lightweight Docker cluster environment than Kubernetes, with many cool features and features.

The above is all the content of this article "what are Kubernetes and Docker?" Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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