MongoDB cluster building

Article directory I. Introduction 1. Preface Two. Start 1. Preparations 1.1. Install MongoDB 1.2 create folder 2. Build a replica set 2.1. Build the replica set of configserver. 2.2. Build the replica set of share service 3. Build a fragment set I. Introduction 1. Preface The environmen ...

Posted on Sat, 18 Jan 2020 03:50:25 -0500 by haixiao

The implementation source code of kubernetes service scatter algorithm

In the distributed scheduling, in order to ensure the high availability and disaster recovery requirements of the service, it is usually said that the service is evenly distributed in multiple areas, racks and nodes, so as to avoid the service unavailability caused by a single point of failure. The algorithm, SelectorSpread, is naturally implem ...

Posted on Sat, 18 Jan 2020 02:05:50 -0500 by d~l

Improvement of decision tree algorithm integrated learning

Improvement of decision tree algorithm integrated learning 1. Definition of integrated learning Using the combination of several weak learning methods (ID3 algorithm, C4.5 algorithm, CART algorithm), we make multiple classification models, that is, multiple decision trees (analog multi expert votin ...

Posted on Fri, 17 Jan 2020 09:42:45 -0500 by johnc71

Function syntax of MySQL database

Learning objectives: master the following sql functions Digital function: format ABS mod ceil floor ground expCharacter function: upper lower char > length concat instrDate function: now date? Format date? Add DateDiff if ifnullConditional function: Numeric function First batch of digital functi ...

Posted on Fri, 17 Jan 2020 09:10:21 -0500 by DKY

Centos7 uses Yum source to install mongodb version 4.2 database

Centos7 uses Yum source to install mongodb version 4.2 database 1. Modify the support of yum installation source for mongodb Official documents available: This month is also built with reference to official documents https://docs.mongodb.com/manual/tutorial/install-mongodb-on-red-hat/#configure-the- ...

Posted on Fri, 17 Jan 2020 08:08:48 -0500 by p0pb0b

C + + Design Pattern -- strategy pattern

Strategy mode In GOF's book "design patterns: the foundation of reusable object-oriented software", the strategic patterns are as follows: define a series of algorithms, encapsulate them one by one, and make them interchangeable. This pattern allows the algorithm to change independently of ...

Posted on Fri, 17 Jan 2020 04:24:37 -0500 by amelhedi

Use of LocalStorage and EssionStorage and JSON conversion

Application of Web Storage Functions: Web Storge enables applications to save program data on the client while the client is running, turning the browser into a real "program running environment" instead of a simple "interface rendering tool" Storage interface: Session Storag ...

Posted on Thu, 16 Jan 2020 21:54:36 -0500 by jc_ply

Build personal OpenAPI

brief introduction OpenAPI Open API is open API, also known as open platform. The so-called open API (OpenAPI) is a common application of service-oriented websites. Website service providers encapsulate their own website services into a series of services API (Application Programming Interface) is open for the use of third-party developers. Thi ...

Posted on Thu, 16 Jan 2020 12:38:05 -0500 by omidh

Django Web framework teaching notes

Catalog Article directory Catalog Query data Field lookup query predicate Modify data record Delete record Aggregate query F object Q object - Q() Native database operation method Query data The query of database needs to use manager object Call the query interface through the MyModel.ob ...

Posted on Thu, 16 Jan 2020 10:21:54 -0500 by scotchegg78

redis programming for python learning

Redis introduction The abbreviation of Redis(Remote Dictionary Server) remote dictionary data service, which is provided by ItalyWhat we developed is a memory cache database. It is written in ANSI C language, supports network, and can be based onIt can also store log and key value databases that can be persisted, and provide API s in multiple ...

Posted on Thu, 16 Jan 2020 10:02:55 -0500 by thebay