• Visitor mode of design mode


    Visitor mode belongs to behavior mode; It refers to separating the operations that act on each element in a data structure and encapsulating them into independent classes, so that they can add new operations that act on these elements without changing the data structure, and provide multiple access methods for each element in the data […]

  • Ali end: talk about the service registry of micro service architecture


    Service registry In the architecture of microservices, service registry is a core concept. As mentioned in the previous section, a service registry is an indispensable part of service discovery. Generally speaking, a service registry is a network address and database that stores network instances. A service registry should be highly available and its data is […]

  • Detailed explanation of the meaning of CSV data set config sharing mode in JMeter


    CSV Data Set Config in Sharing Mode – Made Easy In order to make the performance test more realistic, it is better not to use the same user in each thread group. Therefore, you need a way to configure Apache JMeter ™ To use different users with unique user data, and propose ideas on how […]

  • Structural type: IV proxy pattern


    What is the proxy mode Proxy mode is a structural design mode, which allows you to provide a substitute for the real service object to the client. The proxy receives the client’s request and performs some processing (access control, caching, etc.), and then passes the request to the service object. Why proxy mode In some […]

  • Structural type: v Bridging mode


    What is the bridging mode Bridge mode: bridge is a structural design mode, which can split business logic or a large class into different hierarchies, so that it can be developed independently. Why bridge mode For two independently changing dimensions, the bridging mode is perfect How to implement the bridge mode Here, computer and printer […]

  • CentOS creates a new child user and grants root permission. Root login is prohibited


    Original:https://lwebapp.com/zh/post/c… demand Recently, we encountered a DDoS attack on Alibaba cloud ECS servers, which indicates that our server security needs to be improved. From the aspect of SSH login, you can set up a sub-user for the Linux system and prohibit root login, which can improve a certain degree of security. In this article, you […]

  • Structural type: VI Combination mode


    What is the combination mode Composite mode: it is a structural design mode. You can use it to combine objects into a tree structure and use them as if they were independent objects. Why use composite mode If you need to implement the tree object structure, you can use the composite mode. Ensure that the […]

  • VI editor tips


    ‘vi is a UNIX like operationsystemOne of the most widely used text editors in. This tool is provided by default for UNIX, Solaris, or Linux. It can be said that as long as you are familiar with VI, in any kind of UNIXoperationsystemText editing is freely available on the platform. There are many materials about […]

  • “Free and open source” file upload of the crudapi background management system of the front-end spa project based on Vue and Quasar (10)


    File uploading of front-end spa project based on Vue and Quasar (10) review Pass the previous articleData import of front-end spa project based on Vue and Quasar (IX)This paper mainly introduces the contents related to file uploading. brief introduction Crudapi supports attachment fields. The file URL string is saved in the table field. Attachments can […]

  • Design pattern learning notes (XI) appearance pattern and its application scenarios


    Facade pattern, also known as facade pattern, is a pattern that makes multiple complex subsystems more accessible by providing a consistent interface. For example, in our daily life, the triage desk in the traditional Chinese medicine hospital is a feature that implements a unified access interface: 1、 Appearance mode introduction Skin mode provides a unified […]

  • [Linux] brief introduction to VIM


    What is VIM VIM is a text editor developed from VI. Code completion, compilation, error jump and other convenient programming functions are particularly rich, and are widely used by programmers. Why use VIM Easy to edit files in Linux Environment Three common modes of vim VIM can be divided into three modes: Command mode: control […]

  • 「Golang」sync. Once usage and source code explanation


    preface In our development process, we often use the classic design pattern of singleton mode. Singleton mode can help developers perform initialization or function call operations only once during program operation for a certain variable or object or function (method), such as initialization for a certain type of connection pool (such as database connection pool) […]