RocketMQ for reliable message final consistency

RocketMQ for reliable message final consistency Business description In this case, RocketMQ middleware is used to realize the final consistent distributed transaction of reliable messages and simulate the transfer transaction process of two accounts. Two accounts are in different banks (Zhang San is ...

Added by legomez2000 on Sun, 21 Jun 2020 09:31:11 +0300

Packaging Helm diagrams using Operator technology and deploying them to K8S clusters

Preface In " Packaging and deploying complex applications to the k8s cluster using helm "In this article, we package the application as a chart with helm, which simplifies the deployment process. However, while helm supports Seamless Upgrades for Stateless Applications on the line of Basic Install, replacing the mirrored version to ta ...

Added by kevin_newbie on Fri, 19 Jun 2020 19:26:51 +0300

If BigDecimal is not used properly, the boss's loss will still be deducted from your salary

Yunqi information:[ Click to see more industry information]Here you can find the first-hand cloud information of different industries. What are you waiting for? Come on! We have basically formed a common sense that we need to use BigDecimal instead of others where money is needed, and we all know that floating-point variables will lose precisio ...

Added by keiran420 on Thu, 18 Jun 2020 11:53:31 +0300

How to Design High Performance Distributed Locks

What is a distributed lock? In a JVM, where multiple threads are concurrent, we can use synchronous or Lock locks to ensure that only one thread can modify shared variables or execute code blocks at a time.However, our services are deployed on a distributed cluster basis, and for some shared resources, the use of Java locks in a distributed en ...

Added by gersh on Wed, 17 Jun 2020 19:51:19 +0300

Pandas: from shallow to deep

What is panda? pandas is a NumPy based tool, which is created to solve data analysis tasks. pandas incorporates a large number of libraries and some standard data models, providing the tools needed to efficiently operate large datasets. pandas provides a large number of functions and methods that enab ...

Added by Braveheart on Wed, 17 Jun 2020 06:08:58 +0300

Lab 2 Android Data Storage Instance Address Book

Lab 2 Android Data Storage Instance Address Book 1. Experimental Purpose (1) Skilled in UI interface design process and methods; (2) To further understand the establishment and operation of the SQLite database; (3) Skilled in Andriod database programming. 2. Experimental Environment (1) Hardware: PC, ot ...

Added by tippy_102 on Wed, 17 Jun 2020 04:20:28 +0300

Notes on Mybatis source code: from the perspective of cache system, the distribution mode of responsibility chain and enterprise level practice of circular dependence

1, Cache overview The design of Mybatis cache system follows the principle of single responsibility, opening and closing, and high decoupling. It is exquisite and fully layered, and its unique features can be applied to many similar businesses. Here is a brief analysis of the main caching system. With the help of the learning of Mybatis cache ...

Added by php_b34st on Tue, 16 Jun 2020 11:41:24 +0300

Stored procedure cursor

example: At present, there are three tables A, B and C. among them, A and B are one to many relationships, and B and C are one to many relationships. Now it is necessary to save the primary key of table A in B into C; The general idea is to query out B and update table C with an update statement, bu ...

Added by bobicles2 on Tue, 16 Jun 2020 10:41:40 +0300

django Series 5 - QuerySet API operation

QuerySet API usage QuerySet can construct, filter, slice, and approximate results without actually accessing the database. Unless you do something to evaluate the query set, no query activity actually occurs to the database. (1) Basic properties iteration The QuerySet is iterative, and its databa ...

Added by Phire on Tue, 16 Jun 2020 06:59:36 +0300

Method of Using Redis to Count Web UV s

Article Directory Preface thinking HyperLogLog Use Redis command action Working with Java code The Principle and Feature of HyperLog Implementation Implement HyperLog using Java Summary Preface Web site UV refers to the amount of Unique Visitor visited by independent users of a Web site, that ...

Added by BlueSkyIS on Tue, 16 Jun 2020 03:56:18 +0300