• Ubuntu install kibana


    Preconditions This environment is operated on ubuntu21.04 by default. If you have referred to the previous article, it has been installedElasticSearch。 Then you can jump directly to. Elastic PGP public key and source We need to download and install the public key before installation, otherwise we can’t use apt to install elasticsearch. wget -qO – […]

  • Inversion and covariance in LSP principle


    In the review process, LSP principle is a very important content. Here is the definition of LSP principle. LSP definitionFunctions that use pointers or referrnces to base classes must be able to use objects of derived classes without knowingit. (all places that reference the base class must be able to use the objects of its […]

  • 【GO】go.mod


    go moduleUse preconditions:GO111MODULESet to on Initialize a new module in the current folder and create go Mod file;go mod init name Pull the missing module and remove the unused module:go mod tidy Copy dependency to vendor:go mod vendor Download dependency:go mod download Inspection dependency:go mod verify Display module dependency diagram:go mod graph Explain why you […]

  • Quickly build the development environment of local docker


    ​ summary Windows installation of docker has version restrictions on the system. Because my computer does not support it, I installed the virtual machine of CentOS 8 and explored the use of docker on the virtual machine. Virtual machine installation Download address:http://isoredirect.centos.org/centos/8/isos/x86_64/ Image: = = centos-8.3.2011-x86_ 64-dvd1. iso== Select the network setting of = = […]

  • In the Obsidian VIM mode under MacOS, press and hold J for a long time, and it cannot go down continuously


    According to the online solution for vscode, the solution of obsidian is as follows Preconditions Installing Obsidian Open VIM plug-in The operation is as follows Execute the following command on the command line defaults write md.obsidian ApplePressAndHoldEnabled -bool false Restart obsidian. Then you can experience the VIM experience consistent with Linux.

  • Build NPM private server


    Reference documentshttps://help.sonatype.com/rep… Preconditions Build nexus 3 I Create NPM warehouse 1. Create NX deployer role2. Create a deployer user whose password is also deploy3. Create the hosted, proxy and group of NPM respectively, as shown in the following three figureshosted proxy group 2、 Client Npmrc configuration registry= [email protected] always-auth=true _auth=”ZGVwbG95ZXI6ZGVwbG95ZXI=” _ Auth is the base64 […]

  • Python interface test unittest usage details


    Unittest framework analysis Unittest is the unit test framework of Python. Unittest provides the scheme of creating test cases, test suites and batch execution. Unittest comes directly after installing pyhton, and can be used by importing unittest directly. Open pycharm and import unittest package and requests package Then call unittest Class fortesttest (unittest. Testcase): # […]

  • PostgreSQL slow query statement record and analysis


    1. Record PostgreSQL takes version 12 as an example We need to open the slow query log of PostgreSQL first. This is a precondition. First record our queries for a long time. Edit profile:/var/postgres12/data/postgresql.conf #log_min_duration_statement = -1 # -1 is disabled, 0 logs all statements # and their durations, > 0 logs only # statements […]

  • Understanding restful


    What is restful Restful architecture is the most popular Internet software architecture. It is clear structure, standard, easy to understand, easy to expand, so it is being used by more and more websites. The word rest was proposed by Roy Thomas fielding in his doctoral dissertation in 2000. Rest is the abbreviation of representational state […]

  • Install docker for CentOS


    Environment: Linux centos8 4.18.0-80.el8.x86_ 64、docker-19.03.5 1. Preconditions Requires OS kernel 3.10+ Uname – R // view the operating system version number 2. Check if it is installed (uninstalled) yum remove docker \ docker-client \ docker-client-latest \ docker-common \ docker-latest \ docker-latest-logrotate \ docker-logrotate \ docker-engine You can also uninstall in the following ways: *Yum list […]

  • Performance analysis of azure SQL database


    Preconditions Users have the right to query data statistics GRANT VIEW DATABASE STATE TO database_user; CPU performance issues in progress View the top x CPU consumption queries (summary) SELECT TOP 10 GETDATE() runtime, * FROM ( SELECT query_stats.query_hash, SUM (query_stats.cpu_time) ‘Total_Request_Cpu_Time_Ms’, SUM (logical_reads) ‘Total_Request_Logical_Reads’, MIN (start_time) ‘Earliest_Request_start_Time’, COUNT (*) ‘Number_Of_Requests’, SUBSTRING (REPLACE(REPLACE(MIN (query_stats.statement_text),CHAR (10),’ ‘),CHAR […]

  • Smart database, how to reduce your mental burden?


    Since April 11, we have officially launched a series of live broadcasts with the theme of the future of database. After the first three live broadcasts, we have gradually described the future database in our eyes. Here are some text and video reviews from the third issue of “smart database, how to reduce your mental […]