What is kafka?
Apache Kafka is a distributed message queue based on publish / subscribe mode. It is an open source message system written by Scala. It is mainly used in the field of big data real-time processing and used to process streaming data. It is a very classic message engine and is famous for its high performance and high availability. ...
Posted by Rebel7284 on Fri, 03 Dec 2021 04:02:02 -0800
Transaction is one or more database operations that need to ensure atomicity, isolation, consistency and persistence at the same time
This article will explain the implementation methods of two transactions in springBoot, programming transaction configuration and declarative transaction configuration, as well as aspect transactions. O ...
Posted by Skyphoxx on Tue, 30 Nov 2021 13:34:46 -0800
1, Importance of data backup
In a production environment, data security is critical Any loss of data can have serious consequences Causes of data loss Program error Human operation error Operation error disk failure Disasters (e.g. fire, earthquake) and theft
2, From a physical and logical point of view, backup can be divided into
Posted by patrickm on Mon, 29 Nov 2021 10:19:24 -0800
@SpringBootTest defines that Springboot04JunitApplicationTests is a Test class that supports injecting objects. Once injected, this object can participate in @ Test. Name: @ SpringBootTest Type: test class annotation Location: above the test class definition Function: set the spring boot startup class loaded by JUnit example: ...
Posted by scialom on Mon, 29 Nov 2021 03:56:03 -0800
Pay attention to the official account: big data technology, reply to "information" and receive 1000G information. This article started on my personal blog: Spark SQL knowledge points and actual combat Spark SQL overview
1. What is Spark SQL
Spark SQL is a spark module used by spark for structured data processing. Unlike the basi ...
Posted by lovasco on Fri, 26 Nov 2021 16:41:48 -0800
The purpose of visitor pattern is to encapsulate some operations imposed on some data structure element. Once these operations need to be modified, the data structure that accepts the operation can remain unchanged.
Intent: mainly separate data structure from data operation.
It mainly solves the problems of s ...
Posted by lulon83 on Thu, 25 Nov 2021 19:19:30 -0800
The policy pattern is the packaging of the algorithm. It separates the responsibility of using the algorithm from the algorithm itself and delegates it to different objects for management. Policy patterns usually package a series of algorithms into a series of policy classes as subclasses of an abstract policy ...
Posted by nysmenu on Wed, 24 Nov 2021 19:32:33 -0800
What is IoC?
IoC is the abbreviation of inversion of control. Note that it is a technical idea. It describes the creation and management of objects.
Traditional development methods: for example, if class a depends on class B, it often creates a new object of class B in class A.IoC development method: we don't need to go to the new object ...
Posted by arcanechaos on Fri, 12 Nov 2021 12:32:58 -0800
Each application initializes an application class when it is started. We can do some initialization operations in this class, such as the initialization of a third-party sdk. After the component project is implemented, different business modules also need to do some initialization operations when the application is started. This involv ...
Posted by pete_bisby on Fri, 12 Nov 2021 08:29:36 -0800
Note: the note is about the implementation of page replacement algorithm by fengsigaoju boss( (35 messages) java implements the page replacement algorithm (OPT,FIFO,LRU) _fengsigaoju's blog - CSDN blog _pagereplacement algorithm code java )Learning, invasion and deletion.
I have been learning JAVA for one month. If there are any deficiencies, ...
Posted by ruppelm on Thu, 11 Nov 2021 10:29:03 -0800