• What factors affect MySQL performance?


    1) Connect The connection usually comes from the web server. Here are some connection related parameters and how to set them. 1、max_connections This is the maximum number of connections allowed by the web server. Remember to use session memory for each connection (about session memory, which will be covered later in the article). 2、max_packet_allowed maximumMobile […]

  • Springboot integrates timed tasks and thread pools


    There is a need to “remind regularly at [11:15, 14:15, 16:15, 18:00] on every working day”, which has two difficulties: The daily time is fixed and is not a cycle. It can only be configured to be executed at a fixed time point On weekdays, Saturdays and days need to be excluded, holidays need to […]

  • Introduction to PriorityQueue


      https://www.cnblogs.com/bronya0/p/14408515.html Introduction to PriorityQueue   This thing is called priority queue. It is a class that inherits the abstractqueue class and implements the serializable interface.This is described in the JDK document: Infinite priority queue based on priority heap. The elements of the priority queue are provided according to their ordered natural ordering or by […]

  • JVM basics to online JVM tuning using jemeter (JVM I)


    I. pre knowledge Insert picture description here JDKContains JRE and Java design language. It is the smallest environment for Java language development, namely XXX Java becomes XXX Class minimum environment. JREIncluding Java class library API and virtual machine, it is the standard environment for Java program running. That is, run XXX Class file. JVMAutomatically manage […]

  • Java ~ Parallel Computing ~ parallel processing of large sets


    Last time I wrote about《Functionalinterface ~ a class that processes data in batches》And《Future and callable implement parallel processing of large tasks》This lecture is mainly combined with practical application to encapsulate a set parallel processing component. Our set is divided into pagination set in database query; There is also a memory collection. Today, we mainly talk […]

  • Analysis of AQS source code


    AQS basic structure private transient volatile Node head; // Head node private transient volatile Node tail; // The tail node, each new node, is inserted into the end, which forms a linked list //Indicates the status of the current lock. 0 indicates that it is not occupied. A value greater than 0 indicates that a […]

  • I am the interviewer design pattern – single case pattern


    Design mode – singleton mode In wizard 3, the mount that accompanies the protagonist to march north and south. No matter when and where you call it, it will always have only one name – radish. Hello, I’m Van Gogh with left ear. The article starts with the official account of WeChat, “left ear Van […]

  • Install Arthas locally


    1. Installation address: Click Install 2. The environmental variable is a pit The environment variable should have a JDK with springboot 3. Start java -jar arthas-boot.jar 4.dashboard The dashboard command can view the real-time data panel of the system.Q or Ctrl + C can exit the data display.SC view the class information loaded by the […]

  • Talk about Kafka: the network model of producer


    1、 Network model of producer In the previous articles, we talked about the source code analysis of the producer sending process, but it is a big outline, which involves sending many related contents, such as: Get metadata information of topic Serialization of key and value Get the partition to which the record is sent Append […]

  • How to do resource isolation for 100 million traffic architecture? Well written!


    Author: can’t wait for harmonica Link:https://www.cnblogs.com/Courage129/p/14421585.html Why isolate resources Common resources, such as disk, network, CPU, etc., will have the problem of competition. When building a distributed architecture, you can split the components, modules and resources originally connected together in order to achieve the maximum utilization efficiency or performance. After resource isolation, when some components […]

  • Notes on MySQL 45 lectures


    MySQL infrastructure MySQL logical architecture diagram PNG Connector The connector is responsible for establishing connections with clients, obtaining permissions, maintaining and managing connections. After completing the classic TCP handshake, the connector will start to authenticate your identity. At this time, you use the user name and password you entered. If the user name and password […]

  • Redis or zookeeper for distributed locks


    This paper mainly includes why to use distributed locks and redis as distributed locks, involving redis mode, redisson, redlock, implementation code, implementation principle of using zookeeper, comparison of advantages and disadvantages, etc. Why use distributed locks? Before discussing this issue, let’s take a look at a business scenario: System a is an e-commerce system. At […]