GitHub has officially announced the release of Gh-ost:github's MySQL no-trigger online Change table Definition tool in open source mode!Gh-ost was developed by GitHub in recent months to address a frequently encountered problem: changing product requirements constantly require changes to the MySQL table structure. Gh-ost changes the structure of the online table
GH-Ost practical application I. Installation Steps
1. Environment
Go version: 1.10.3gh-Ost version: 1.0.46
2. Install the go Language
# Install go dependency package Yum install bison ed gawk GCC libc6-dev make-y # configure go environment variable Vim ~ /. Bashrcexport goroot =/usr/local/goexport Path = $ path: $ goroot/binexport gopath =/usr/local/go/src/github.com/github/gh-ost# make the environment vari
Country domain name as a unique existence, first of all to give people the first impression is to think of a country's Domain name field representative. Looking back on the past year, a lot of country domain names are high-priced, meaning has always been the evaluation of the value of the name of one of the important factors, the same, in the country domain name is no exception. Today's small series to discuss with you in the wind in the standing of the GH
Gh-ost Use test:gh-ost-host= ' 192.168.65.136 '-user=root-password= '-database= ' haha '-chunk-size=100000-allow-on-master-execute- Initially-drop-ghost-table-exact-rowcount--initially-drop-old-table-alter= ' modify Areaid varchar (ten) '-table= ' T_ Policyarea '-allow-master-Master explicitly allows running in the primary primary cluster-allow-on-Master allows to run directly on the host, if no cluster uses this option, it is recommended to use on-ma
GH-Ost Test
1. Tables without primary keys or with unique indexes are not supported.
2018-08-24 09:53:33 FATAL No PRIMARY nor UNIQUE key found in table! Bailing out
2. Tables with foreign key constraints are not supported (neither the primary table nor the subtable are supported)
2018-08-24 10:03:09 ERROR Found 1 parent-side foreign keys on `darren`.`t1`. Parent-side foreign keys are not supported. Bailing out2018-08-24 10:03:09 INFO Tearing down insp
People with GitHub know that the master branch is simply browsing the code and cannot open the page directly to the page, while the Gh-pages branch is the branch that is used to directly browse the source page.
The process of submitting the Master branch to the Gh-pages branch and then submitting it again after each modification is obviously tedious.
Of course, you can use git rebase command to simplify t
GH-OST principle 1. Architecture diagram of three modes
1. Connect to the slave database and modify it on the master database
This is the default Operating Mode of GH-ost. It will check the slave database status, find the master database of the cluster, and connect to it. It has the least intrusion to the master database. The general steps are as follows:
Create _ xxx_gho and _ xxx_ghc on the master databas
IOSApplication UsageGH-UnitProceedUnit TestThis is the content to be introduced in this article. If you don't want to talk about it, go directly to the topic and first introduce the content framework.
Unit Test iOSXcode framework project management
1. Objective of Unit Testing
2. Ensure code correctness
Support for future code refactoring
1. Basic Environment:
2. computers using the apple System
XCode
GH-Unit is a powerful Unit testing framework devel
Os:centos 6.5Db:percona Server 5.6.32gh-ost:1.0.21db-m:192.168.128.128Db-s: 192.168.128.129Brief introduction:Gh-ost is an open source tool for online SQL execution on GitHub. Can be used for online table structure changes (especially large tables, for reasons below)Online table structure changes, currently commonly used in the following ways:1. Small table: Online DDL (5.6 and later versions)Create a temporary table for the changed table structure, update the temporary table data, and record th
Trojan. DL. win32.autorun. yuz, Trojan. win32.inject. gh, Trojan. win32.agent. zsq, etc.
EndurerOriginal2007-10-231Version
Pe_xscan 07-08-30 by Purple endurer2007-10-22 13:13:44Windows XP Service Pack 2 (5.1.2600)Administrator user group
C:/Windows/system32/winlogon.exe * 604 | MICROSOFT (r) Windows (r) Operating System | 5.1.2600.2180 | Windows NT logon application | (c) Microsoft Corporation. all rights reserved. | 5.1.2600.2180 (xpsp_sp2_rtm.040803
/helloworld/ Access.Enabling the Project home page for your project is simple, just create a branch named gh-pages in the project repository and add a static Web page to it. That is, if the project's Git repository contains a gh-pages branch, it means that the project provides a home page composed of static pages that can be http:// access to.The following is an example of a user Gotgithub project HelloWorl
Countdownlatch is capable of waking up multiple waiting threads.The thread that reaches its expected state calls the Countdownlatch countdown method, and the waiting thread calls the Countdownlatch await method. If the count value of Countdownlatch initialization is 1, then this is degraded to a single event, that is, a thread notifies other threads, and the effect is equal to the object's wait and Notifyall,count values greater than 1 are common ways The goal is to have multiple threads reach
The interview encountered such a problem: threads A and thread B, how to control thread B in line a start 3 seconds or after thread a runs to start?The topic shows that thread B's start-up time is to meet two conditions:1. After thread a starts 3 seconds2. After the end of thread a runsThis means that as long as the above two conditions have a satisfying, thread B will start.Use Countdownlatch to control call timing, the code is as follows:1 Public classRunAImplementsRunnable {2 PrivateCoun
a CDL File(The specific format of the CDL file is described in the next section ).Temperature: Units = "Celsius ";The previous temperature is a defined variable (variable), that is, temperature. The units after the colon is the attribute name,Indicates the physical unit. = the value of the units attribute is "Celsius", that is, degree celsius. The entire line of code indicatesThe unit of temperature is Cel
a CDL File(The specific format of the CDL file is described in the next section ).Temperature: Units = "Celsius ";The previous temperature is a defined variable (variable), that is, temperature. The units after the colon is the attribute name,Indicates the physical unit. = the value of the units attribute is "Celsius", that is, degree celsius. The entire line of code indicatesThe unit of temperature is Cel
. For example, in a CDL File(The specific format of the CDL file is described in the next section ).Temperature: Units = "Celsius ";The previous temperature is a defined variable (variable), that is, temperature. The units after the colon is the attribute name,Indicates the physical unit. = the value of the units attribute is "Celsius", that is, degree celsius. The entire line of code indicatesThe unit of t
Countdownlatch is capable of waking up multiple waiting threads.The thread that reaches its expected state calls the Countdownlatch countdown method, and the waiting thread calls the Countdownlatch await method. If the count value of Countdownlatch initialization is 1, then this is degraded to a single event, that is, a thread notifies other threads, and the effect is equal to the object's wait and Notifyall,count values greater than 1 are common ways The goal is to have multiple threads reach
(Calendar. MINUTE) + 30); // one in 5 chances of reversing the direction: an opportunity to reverse the direction at 5: if (rand. nextInt (5) = 4) {tempDirection =-tempDirection; // Toward} // store previous value: the value before the store: lastTemp = lastTemp + tempDirection * (1.0f + rand. nextFloat (); if (rand. nextInt (5) = 4) {humidityDirection =-humidityDirection;} lastHumidity = lastHumidity + humidityDirection * rand. nextFloat (); // calendar must be cloned, otherwise all // dataPoi
Control the startup sequence of two threads.
In the interview, I encountered the following question: How can I control thread B to start after thread A starts for 3 seconds or after thread A finishes running?
The question shows that thread B's start time must meet two conditions:
1. 3 seconds after thread A starts
2. After thread A finishes running
That is to say, as long as one of the above two conditions is met, thread B will start.
Use CountDownLatch to control the call sequence. The Code is
understand them very quickly.2. Dimension (Dimension)A dimension corresponds to an argument in a function, or an axis in a function image, which is an n-dimensional vector in linear algebra.(This is also the origin of the name of the dimension). In netCDF, a dimension has a name and range (or length,is a mathematically defined domain, which can be a discrete set of points or a continuous interval. In netCDF, the length of the dimension is basically limited,There can be at most one dimension wit
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