Linux– Process priority and environment variables

Directory process priority basic concept How to check priority PRI and NI NI value setting range How to modify the NI value Modification method 1: Modify the priority through the top command Modification method 2: Modify the priority through the renice command Four important concepts of process environment variable basic concept Common Environment Variables View […]

A variety of tools work together to create a CentOS-based image containing the latest version of sysstat

Sysstat is deployed on the server, and system monitoring records can be kept through sar. It is not very convenient to download data from the server for analysis elsewhere, so consider building a convenient Docker image to assist in the work. sysstat: 1. Bing AI creates Dockerfile Let AI help write Dockerfile directly The […]

Class variables, class methods, code blocks, abstract classes, interfaces, and inner classes

After learning about encapsulation, inheritance, and polymorphism in object-oriented programming, I recently came into contact with several new knowledge points. Sort it out here, help yourself to review, and also record my learning experience. 1. Class variables and class methods Instance objects of the same class only share a template prototype, and do not share […]

Python’s various network request libraries urllib3 requests aiohttp request http and https efficiency comparison, multi-threading, gevent, asyncio comparison, super large thread pool, 2n + 1 thread pool comparison…

The three purposes of this article are not to go astray by just obsessing with concepts. Some people think that there is a set of concepts, but in fact it is not what they think. This article uses various network request libraries, various concurrency modes, and thread pools of various sizes to test 50,000 requests […]

Shell variable functions

What is a variable? ? It should be easy to understand, y=ax + b, y is a variable, ax + b is the content of the variable, the left side of the equal sign is an unknown number, and the right side of the equal sign is a known number. Simply put, a variable is […]

Database – the difference between various functions of SQL Sever and MySQL

Directory 1. Scalar functions (built-in functions & amp; custom functions) 1. The basic syntax of the scalar function of SQL Server is as follows: 2. The scalar function of MySQL adopts the following syntax: 3. Difference 2. Stored procedure Third, the difference between stored procedures and scalar functions 4. Partition function (partition table) 5. Trigger […]

Various implementations of Spring Boot operating Redis

1. The difference between Jedis, Redisson, and Lettuce What they have in common: Both provide Java APIs based on Redis operations, but the degree of encapsulation and specific implementation are slightly different. difference: 1.1、Jedis is a client for the Java implementation of Redis. Support basic data types such as: String, Hash, List, Set, Sorted Set. […]