Skip to main content

Home/ Larvata/ Group items tagged programming

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
張 旭

Connection and Privileges Needed - 0 views

www.percona.com/...privileges.html

mysql database backup percona xtradb

shared by 張 旭 on 02 Dec 19 - No Cached
  • Percona XtraBackup needs to be able to connect to the database server and perform operations on the server and the datadir when creating a backup, when preparing in some scenarios and when restoring it.
  • When xtrabackup is used, there are two actors involved: the user invoking the program - a system user - and the user performing action in the database server - a database user.
  • these are different users in different places, even though they may have the same username.
  • ...1 more annotation...
  • Once connected to the server, in order to perform a backup you will need READ and EXECUTE permissions at a filesystem level in the server’s datadir.
  • 張 旭 on 02 Dec 19
     
    "Percona XtraBackup needs to be able to connect to the database server and perform operations on the server and the datadir when creating a backup, when preparing in some scenarios and when restoring it. "
張 旭

Incremental Backup - 0 views

www.percona.com/...incremental_backup.html

mysql database backup percona xtradb

shared by 張 旭 on 02 Dec 19 - No Cached
  • xtrabackup supports incremental backups, which means that they can copy only the data that has changed since the last backup.
  • You can perform many incremental backups between each full backup, so you can set up a backup process such as a full backup once a week and an incremental backup every day, or full backups every day and incremental backups every hour.
  • each InnoDB page contains a log sequence number, or LSN. The LSN is the system version number for the entire database. Each page’s LSN shows how recently it was changed.
  • ...18 more annotations...
  • In full backups, two types of operations are performed to make the database consistent: committed transactions are replayed from the log file against the data files, and uncommitted transactions are rolled back.
  • You should use the --apply-log-only option to prevent the rollback phase.
  • An incremental backup copies each page whose LSN is newer than the previous incremental or full backup’s LSN.
  • Incremental backups do not actually compare the data files to the previous backup’s data files.
  • you can use --incremental-lsn to perform an incremental backup without even having the previous backup, if you know its LSN
  • Incremental backups simply read the pages and compare their LSN to the last backup’s LSN.
  • without a full backup to act as a base, the incremental backups are useless.
  • The xtrabackup binary writes a file called xtrabackup_checkpoints into the backup’s target directory. This file contains a line showing the to_lsn, which is the database’s LSN at the end of the backup.
  • from_lsn is the starting LSN of the backup and for incremental it has to be the same as to_lsn (if it is the last checkpoint) of the previous/base backup.
  • If you do not use the --apply-log-only option to prevent the rollback phase, then your incremental backups will be useless.
  • run --prepare as usual, but prevent the rollback phase
  • If you restore it and start MySQL, InnoDB will detect that the rollback phase was not performed, and it will do that in the background, as it usually does for a crash recovery upon start.
  • xtrabackup --prepare --apply-log-only --target-dir=/data/backups/base \ --incremental-dir=/data/backups/inc1
  • The final data is in /data/backups/base, not in the incremental directory.
  • Do not run xtrabackup --prepare with the same incremental backup directory (the value of –incremental-dir) more than once.
  • xtrabackup --prepare --target-dir=/data/backups/base \ --incremental-dir=/data/backups/inc2
  • --apply-log-only should be used when merging all incrementals except the last one.
  • Even if the --apply-log-only was used on the last step, backup would still be consistent but in that case server would perform the rollback phase.
張 旭

Java microservices architecture by example - 0 views

www.scnsoft.com/...java-microservices-example

java micro service architecture programming

shared by 張 旭 on 26 Oct 18 - No Cached
baliar liked it
  • A microservices architecture is a particular case of a service-oriented architecture (SOA)
  • What sets microservices apart is the extent to which these modules are interconnected.
  • Every server comprises just one certain business process and never consists of several smaller servers.
  • ...12 more annotations...
  • Microservices also bring a set of additional benefits, such as easier scaling, the possibility to use multiple programming languages and technologies, and others.
  • Java is a frequent choice for building a microservices architecture as it is a mature language tested over decades and has a multitude of microservices-favorable frameworks, such as legendary Spring, Jersey, Play, and others.
  • A monolithic architecture keeps it all simple. An app has just one server and one database.
  • All the connections between units are inside-code calls.
  • split our application into microservices and got a set of units completely independent for deployment and maintenance.
  • Each of microservices responsible for a certain business function communicates either via sync HTTP/REST or async AMQP protocols.
  • ensure seamless communication between newly created distributed components.
  • The gateway became an entry point for all clients’ requests.
  • We also set the Zuul 2 framework for our gateway service so that the application could leverage the benefits of non-blocking HTTP calls.
  • we've implemented the Eureka server as our server discovery that keeps a list of utilized user profile and order servers to help them discover each other.
  • We also have a message broker (RabbitMQ) as an intermediary between the notification server and the rest of the servers to allow async messaging in-between.
  • microservices can definitely help when it comes to creating complex applications that deal with huge loads and need continuous improvement and scaling.
crazylion lee

getify/You-Dont-Know-JS: A book series on JavaScript. @YDKJS on twitter. - 0 views

github.com/...You-Dont-Know-JS

javascript ebook programming books

shared by crazylion lee on 11 Sep 16 - No Cached
  • crazylion lee on 11 Sep 16
     
    "This is a series of books diving deep into the core mechanisms of the JavaScript language. The first edition of the series is now complete."
crazylion lee

Polygonal Map Generation for Games - 0 views

www-cs-students.stanford.edu/...polygon-map-generation

maps map gamedev generation game terrain

shared by crazylion lee on 20 Aug 16 - No Cached
  • crazylion lee on 20 Aug 16
     
    "I wanted to generate interesting game maps that weren't constrained to be realistic, and I wanted to try some techniques I hadn't tried before. I usually make tile maps but instead used a different structure. What could I do with 1,000 polygons instead of 1,000,000 tiles? The distinct player-recognizable areas might be useful for gameplay: locations of towns, places to quest, territory to conquer or settle, landmarks, pathfinding waypoints, difficulty zones, etc. I generated maps with polygons, then rasterized them into tile maps that looked like this:"
crazylion lee

Applying the Linus Torvalds "Good Taste" Coding Requirement - Medium - 0 views

medium.com/...oding-requirement-99749f37684a

programming linustorvalds C linux

shared by crazylion lee on 24 Nov 16 - No Cached
  • crazylion lee on 24 Nov 16
     
    "Applying the Linus Torvalds "Good Taste" Coding Requirement"
張 旭

Service objects in Rails will help you design clean and maintainable code. Here's how. - 0 views

www.netguru.co/...ice-objects-in-rails-will-help

service rails programming controller model pattern object

shared by 張 旭 on 30 Nov 16 - No Cached
  • Services has the benefit of concentrating the core logic of the application in a separate object, instead of scattering it around controllers and models.
  • Additional initialize arguments might include other context information if applicable.
  • And as programmers, we know that when something can go wrong, sooner or later it will!
  • ...7 more annotations...
  • we need a way to signal success or failure when using a service
  • what ActiveRecord save method uses
  • if the services role is to create or update rails models, it makes sense to return such an object as result.
  • utility objects to signal success or error
  • services will be used on the boundary between user interface and application
  • All the business logic is encapsulated in services and models
  • how we can use Service Objects, Status Objects and Rails’s Responders to produce a nice, consistent API
張 旭

Using Services to Keep Your Rails Controllers Clean and DRY - 0 views

blog.engineyard.com/...-controllers-dry-with-services

ruby rails service programming pattern object

shared by 張 旭 on 30 Nov 16 - No Cached
  • I’ll typically create an actions folder for things like create_invoice, and folders for other service objects such as decorators, policies, and support. I also use a services folder, but I reserve it for service objects that talk to external entities, like Stripe, AWS, or geolocation services.
  • You can create your own actions, decorators, support objects, and services.
張 旭

Building a RESTful API in a Rails application - 0 views

www.airpair.com/...ful-api-in-a-rails-application

rails api REST

shared by 張 旭 on 05 Dec 16 - No Cached
  • designing and implementing a REST API in an intentionally simplistic task management web application, and will cover some best practices to ensure maintainability of the code.
  • each individual request should have no context of the requests that came before it.
  • each request that modifies the database should act on one and only one row of one and only one table
  • ...10 more annotations...
  • The resource endpoints should return representations of the resource as data, usually XML or JSON.
  • POST for create, PUT for update, PATCH for upsert (update and insert).
  • an existing API should never be modified, except for critical bugfixes
  • Rather than changing existing endpoints, expose a new version
  • using unique database ids in the route chain allows users to access short routes, and simplifies resource lookup
  • while exposing internal database ids to the consumer and requiring the consumer to maintain a reference to ids on their end
  • The downfall is longer nested routes
  • require reauthentication on a per-request level
  • Devise.secure_compare helps avoid timing attacks
  • Defensive programming is a software design principle that dictates that a piece of software should be designed to continue functioning in unforeseen circumstances.
crazylion lee

6.851: Advanced Data Structures - 1 views

courses.csail.mit.edu/6.851

MIT CS data structures programming course

shared by crazylion lee on 04 Dec 16 - No Cached
  • crazylion lee on 04 Dec 16
     
    "Welcome to Advanced Data Structures, a graduate class at MIT. Please choose your semester:"
crazylion lee

The Bash Academy - 0 views

www.bash.academy

bash programming tutorial linux

shared by crazylion lee on 08 Dec 16 - No Cached
  • crazylion lee on 08 Dec 16
     
    "The Bash Academy is an initiative to promote the bash shell language and educate people on its use. "
張 旭

React 入门实例教程 - 阮一峰的网络日志 - 0 views

www.ruanyifeng.com/...react.html

javascript programming web frontend react

shared by 張 旭 on 23 Jan 17 - No Cached
  • React 起源于 Facebook 的内部项目，因为该公司对市场上所有 JavaScript MVC 框架，都不满意，就决定自己写一套，用来架设 Instagram 的网站。
  • 项目本身也越滚越大，从最早的UI引擎变成了一整套前后端通吃的 Web App 解决方案
  • React Native 项目，目标更是宏伟，希望用写 Web App 的方式去写 Native App。
  • ...9 more annotations...
  • 凡是使用 JSX 的地方，都要加上 type="text/babel"
  • Browser.js 的作用是将 JSX 语法转为 JavaScript 语法，这一步很消耗时间，实际上线的时候，应该将它放到服务器完成。
  • HTML 语言直接写在 JavaScript 语言之中，不加任何引号，这就是 JSX 的语法，它允许 HTML 与 JavaScript 的混写
  • JSX 的基本语法规则：遇到 HTML 标签（以 < 开头），就用 HTML 规则解析；遇到代码块（以 { 开头），就用 JavaScript 规则解析。
  • JSX 允许直接在模板插入 JavaScript 变量。如果这个变量是一个数组，则会展开这个数组的所有成员
  • 所有组件类都必须有自己的 render 方法，用于输出组件
  • 组件类的第一个字母必须大写，否则会报错
  • 组件类只能包含一个顶层标签
  • 添加组件属性，有一个地方需要注意，就是 class 属性需要写成 className ，for 属性需要写成 htmlFor ，这是因为 class 和 for 是 JavaScript 的保留字。
crazylion lee

Gaffer on Games | Game Networking - 0 views

gafferongames.com/etworking-for-game-programmers

game networking programming

shared by crazylion lee on 30 Jan 17 - No Cached
  • crazylion lee on 30 Jan 17
     
    "Game Networking"
crazylion lee

The USE Method - 0 views

www.brendangregg.com/usemethod.html

performance programming

shared by crazylion lee on 30 Jan 17 - No Cached
  • crazylion lee on 30 Jan 17
     
    "The Utilization Saturation and Errors (USE) Method is a methodology for analyzing the performance of any system. It directs the construction of a checklist, which for server analysis can be used for quickly identifying resource bottlenecks or errors. It begins by posing questions, and then seeks answers, instead of beginning with given metrics (partial answers) and trying to work backwards."
« First ‹ Previous 41 - 60 of 174 Next › Last »
Showing 20▼ items per page