Programming VIP

This article describes how to deploy a sharded database with adg function. 1. Environment introduction The roles and database versions of each node are shown in the following table:The instance name is named by the system itself. 2. Create Shard Catalog Database Here we use the silent method to create the directory database on odb01. [oracle@o ...

The stack is changed by linear performance. Linear table is very free. You can insert data wherever you want, and delete data wherever you want. But there are some restrictions on the linear table, so it is not so free. Sealing the three sides of the linear table turns into a stack. The stack can only be "first in first out". In reali ...

text Let's use java code to crawl the csdn blog site, and then automatically comment. This wave of operation can be said to be quite coquettish. Let's go to the code. The first step is the login code, which is a large part of the Internet. The code uses the JSP dependency package to parse html to get the corresponding elements, which is equival ...

[TOC] I. fsimage and edit files 1. Basic concepts txid: namenode gives a unique id for each operation event (add, delete, and change operation), which is called txid. Generally, txid is automatically increased from 0. For each additional operation, txid is automatically increased by 1. fsimage: It is a mirror file of the metadata of namenode i ...

Production and Construction Environment:Operating System: CentOS 7.5Memory size: 32GBHard disk: 1TNote: The optimization of the kernel parameters in the text is modified according to the actual environment.1. Software preparation for installation1.1 Software preparation jdk-8u161-linux-x64 http://www.oracle.com ORACLE linux.x64_11gR2_databas ...

1. Download the installation package wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-6.8.3.tar.gz After downloading, decompress. The address I decompressed is: / usr / local / elastic search 6.8.3 2. Creating Users es cannot run as root, so you need to create users adduser elastic #Create elastic users Cre ...

Introduction to High Availability High Availability of Hadoop can be divided into HDFS high availability and YARN high availability. Their implementation is basically similar, but HDFS NameNode requires much higher data storage and consistency than YARN Resource Manger, so its implementation is more complex. So let's explain the following: 1.1 ...

1. Method overload 1. Also known as overload 2. Method overload usage scenarios When functionality is similar, try to keep method names the same as possible (but when functionality is different or different, method names are as different as possible) 3. After what conditions are met, method overload can be constituted (1) in the same class ...

ZooKeeper's election process defaults to the FastLeaderElection class, which starts Messenger to send and receive election information when FastLeaderElection starts. After the election is completed, one Leader and several Follower are selected. First understand several concepts: Epoch: The voting cycle is used to distinguish each round, and ...

Introduction of Technology Stack Front end part: react v16.8 family bucket (react,react-router): MVVM framework for building user interface redux: Famous JavaScript State Management Container redux-thunk: redux middleware for handling asynchronous logic immutable: Facebook's three-year-old library for persistent data structure processing (it ...