Programmer Think

preface In a normal production environment, we sometimes encounter host disk and other hardware failures that cause the host OS system to fail to start, or the OS system itself fails to repair. At this time, there is no other way except to reinstall the OS system, but how to join the original RAC cluster after reinstallation 👇👇 The followin ...

** introduction ** TCP/IP communication (i.e. SOCKET communication) is the communication established through TCP/IP protocol on the basis of following the four-tier architecture of ISO/OSI model by connecting the Server end of the Server and the Client end of the Client through the network cable. The controller can be set as Server or Client. ...

1. Start process of Container stay Tomcat source code analysis (1) - structure composition and core components In, the author analyzes the general composition of Tomcat. The Container container is a core component strongly related to the upper business logic, and is divided into four levels. During the startup of tomcat, the startup proces ...

1, What is a Session Session is an interface (HttpSession).A Session is a Session. It is a technology used to maintain an association between a client and a server.Each client has its own Session.In the Session session, we often use it to save the information after the user logs in. 2, How to create a Session and get (id number, new or not) H ...

ls Abbreviation of common parametersFull name of parameterdescribe-a--allList all files in the directory, including "." Implied file at the beginning-lIn addition to the file name, the file permission, owner, file size and other information are listed in detail-h--human-readableList file sizes in an easy to understand format-tSor ...

Domain name system Domain name system (DNS) is mainly used for the mapping between host name and IP address. The host name can be either a simple name, such as solaris or bsdi, or a fully qualified domain name (FQDN), such as solaris unpbook. com . resource record Entries in DNS are called resource records (RR s). A. A record maps a ho ...

Shared memory allows two unrelated processes to access the same logical memory. It is a very effective way to transfer data between two running processes. Most of the specific implementations of shared memory arrange the memory shared by different processes into the same physical memory. Shared memory is a special address range created by I ...

What is? Reverse proxy The reverse proxy server determines which server provides services. The return proxy server does not provide a server. Just request forwarding. The forward proxy is as follows Reverse proxy is as follows   Nginx The process of implementing reverse proxy First, install two tomcat servers and put them into the ngin ...

Detailed explanation of SSH service (IV) -- local calling command of remote host The SSH server runs on ubuntu 18.04.1SSH client in Windows10 This section mainly explains that ssh calls commands on the remote host locally without logging in to the remote host shell Application scenario: In the actual shell script writing process, you need t ...

WebSocket Background: The HTTP protocol has a flaw: communication can only be initiated by the client. This one-way request is doomed to be very troublesome for the client to know if the server has continuous state changes. We can only use "Polling" : every once in a while, send a query to see if the server has any new information. ...