Tag: uti

[PG] PostgreSQL high availability solution repmgr deployment (very detailed)

Table of Contents Introduction 1 Overview 1.1 Terminology 1.2 Components 1.2.1 repmgr 1.2.2 repmgrd 1.3 Repmgr users and metadata 2 Installation and deployment 2.0 Deployment environment 2.1 Installation requirements 2.1.1 Operating system 2.1.2 PostgreSQL version 2.1.3 Operating system users 2.1.4 Installation location 2.1.5 Version requirements 2.2 Installation 2.2.1 Software package installation 2.2.2 Source code compilation […]

[PG] Configuration file for PostgreSQL high availability solution repmgr management

1 Configuration File 1.1 Configuration file format repmgr.conf is a plain text file containing one parameter/value combination per line. White spaces are irrelevant (except within quoted parameter values), and blank lines are ignored. #Specifies the remainder of the line as a comment. Parameter values that are not simple identifiers or numbers should be enclosed in […]

[Linux] dns domain name resolution service

1. DNS 1.1 Introduction to DNS Domain name resolution: (English: Domain Name System, abbreviation: DNS) is a service of the Internet. As a distributed database that maps domain names and IP addresses to each other, it can make people access the Internet more conveniently. DNS uses udp53 and tcp53. Currently,the length limit for each level […]

A “flyweight” C language coroutine library

Coroutine, as its name implies, is “co-operative routines”. Unlike threads with operating system concepts, coroutines are programming techniques that can achieve logical multitasking in user space by using the syntax and semantics of programming languages. In fact, the concept of coroutine is earlier than thread. According to Knuth, “Subroutine is a special case of coroutine”. […]

How C/C++ runs and its distribution in memory

C/C++ Restart? 1.0 Question: How does the written C++ code run? In the following order from left to right Writing source code Preprocessing Compilation Assembly Linking Loading Execute() Writing source code: writing in high-level programming languages, such as following C/C++ syntax rules to write good code correctly Preprocessing: Before compilation, the preprocessor processes header files […]

[Geek Challenge 2019]BuyFlag 1 (two solutions)

Question environment: FLAG NEED YOUR 100000000 MONEY Flag needs your 100,000,000 yuan F12 Take a look at the source code: if (isset($_POST[‘password’])) {<!– –> $password = $_POST[‘password’]; if (is_numeric($password)) {<!– –> echo “password can’t be number” } elseif ($password == 404) {<!– –> echo “Password Right! } } PHP code audit: Two parameters password and […]

Unity data reading | (4) Json file parsing (Newtonsoft.Json, Litjson, JsonUtility, SimpleJSON)

Directory 1 Introduction 2. Advantages and Disadvantages 3. Analysis 3.1 Newtonsoft.Json 3.1.1 Download address 3.1.2 Advantages and Disadvantages 3.1.3 Analysis 3.2 listjson 3.2.1 Download address 3.2.2 Advantages and Disadvantages 3.2.3 Analysis 3.3 JsonUtility 3.3.1 Advantages and Disadvantages 3.3.2 Analysis 3.4 SimpleJSON 3.4.1 Download address 3.4.2 Advantages and Disadvantages 3.4.3 Analysis 4. Summary 1. Preface A […]

Solution to “Python3.12pip network installation library file error, ssl module is unavailable”

Solution to “Python3.12pip network installation library file error, ssl module is unavailable” 1. Install the new version of openssl3.1.4 2. Install Python3.12.0 The Python version needs to match the openssl version. In versions after Python 3.7, the dependent openssl must be a version after 1.1.1 or 1.0.2, and the openssl1.0.2k installed in CentOS7 cannot meet […]

Linux performance optimization using Tuned configuration optimization solution

Write in front Organizing notes related to exams The blog post covers a simple understanding of Linux tuned tuning tools A brief description of tuning configuration files and an introduction to custom tuning solutions If you don’t understand enough, please help me correct it. There is only one true responsibility for everyone: to find themselves. […]