Small program cloud development: rookies can also make full-stack products
Why is it so difficult to implement a full stack product independently In our daily life, we use many software products. When using these products, what we can see is called "front-end interface" such as an input box, a button, and all the invisible things that happen after clicking the button are called "back-end services". The corresponding creators are called "front-end pro
Spring Cloud Alibaba Learning (1): Running Nacos
Next: Spring Cloud Alibaba Learning (2): Unified Management of Dependencies As a registry, Nacos provides services such as registration and discovery, configuration management and other functions. Download address: https://github.com/alibaba/nacos/releases Download the compressed package, decompress it and enter the bin to execute # windows stand-alone
Spring Cloud Alibaba Learning (2): Unified Management of Dependencies
Previous: Spring Cloud Alibaba Learning (1): Running Nacos Next: Spring Cloud Alibaba Learning (3): Service Provider IDEA creates a maven project and names the project name:  After writing in pom.xml , the dependencies will be shared by submodules.  The versions used here are: spring boot: 2.3.12.RELEASEspring cloud: Hoxton.SR12spring cloud alibaba:
Docker & Kubenetes Series 3: Deploying a Single Service Instance in k8s
This chapter will explain: the concept of pod and how to deploy a single application instance to k8s. In the above pages, we learned about docker, made and ran the docker image, and then published the image to the central repository. Then build the local k8s environment. This article will demonstrate how to deploy a single service instance to k8s. Meaning of Pod The smallest
Docker & Kubenetes Series 2: Building a native k8s environment
This article will explain what is k8s? The local k8s environment is built, a pod is deployed and several kubectl commands are demonstrated, and the k8s dashboard is installed. what is k8s k8s is the abbreviation of kubernetes, which is a brand-new leading solution for distributed architecture based on container technology . It is an open-source version of Borg, a large-scale
Docker & Kubenetes Series 2: Building a native k8s environment
This article will explain what is k8s? The local k8s environment is built, a pod is deployed and several kubectl commands are demonstrated, and the k8s dashboard is installed. what is k8s k8s is the abbreviation of kubernetes, which is a brand-new leading solution for distributed architecture based on container technology . It is an open-source version of Borg, a large-scale
A picture to see the various Queues in Java
When it comes to data structures, we can probably list a few: arrays, linked lists, stacks, queues, sets, and hash tables. Among them, the queue is a commonly used data structure, and there are various forms of implementation in Java. The top-level interface is java.util.queue. In the java.util package, there are multiple implementations in the java.util.concurrent package. It
Detailed explanation of Java collection classes
Collection ├List │├LinkedList │├ArrayList │└Vector │ └Stack └Set Map ├Hashtable ├HashMap └WeakHashMap Collection interface   Collection is the most basic collection interface. A Collection represents a group of Objects, that is, the elements of the Collection. The Java SDK does not provide classes that inherit directly from Collection. The classes provi
Spring Cloud Alibaba Learning (3): Service Provider
Previous: Spring Cloud Alibaba Learning (2): Unified Management of Dependencies Next: Spring Cloud Alibaba Learning (4): Service Consumers Right-click the parent module in IDEA, select New→Module, and follow the prompts to create a submodule named Provider Write this submodule as a web project . pom.xml _ Introduce two dependencies: spring-boot-star
Internal Interfaces in Java
Read the table of contents #What is an internal interfaceWhy use an internal interfaceHow inner classes workInternal interface exampleTranslation link What is an internal interface # An inner interface is also called a nested interface, that is, an interface is defined inside another interface. For example, the Entry interface is defined in the Map interface, with the following
javap study diary~2
 Now that we have some understanding of javap, let's start using it to solve some practical problems:   1. Problems with i++ and ++i   The result of decompilation is    Code:   0: iconst_1   1: istore_1   2: iinc 1, 1 //This instruction increases the local variable 1, i.e. i, by 1. This instruction will not cause the stack to change, i now becomes
About the role and difference of construction code block, local code block and static code block
Construct the code block:   The code block defined directly in the class without the static keyword is called {} construction code;   Role: uniformly initialize data to the object     public class Demo1 { public static void main(String[] args) { Test test = new Test(3); // The construction code block will be executed when the constructor is called, and in th
What is ANSI encoding?
Create a text file text.txt with Notepad++, the default encoding format is ANSI (at first glance, I thought it was ASCII), the input Chinese characters are not garbled: Save it as test.txt and send it to your colleague Bob in the US. He also uses Notepad++, unfortunately, but finds that your file content is like this: Maybe you think: you are using a Chinese system, which ca
Popular science: Why does the String hashCode method choose the number 31 as the multiplier
1. Background One day, when I was writing code, I accidentally clicked on the String hashCode method. Then I took a general look at the implementation of hashCode and found that it is not very complicated. But I found a strange number from the source code, which is the main character 31 of this article. This number is not declared as a constant, so there is no way to literally
Maven: Difference between mirror and repository
Internal repository refers to the repository built inside the local area network. The difference between it and the central repository, jboss repository, etc. is only that its URL is an internal URL  mirror, which is equivalent to a proxy. It will intercept the request to download the component from the specified remote repository, and then Find the comp
Android application component Content Provider brief introduction and learning plan
        In the Android system, Content Provider, as one of the four components of an application, plays a role in sharing data between applications, and at the same time, it is also a standard data access interface. The previous series of articles have analyzed the other three components of Android applications (Activity, Service and Broadcast Receiver). Th
How many rows of data can a B+ tree in InnoDB store?
one question? How many rows of data can a B+ tree in InnoDB store? The simple answer to this question is: about 20 million. Why so many? Because this can be calculated, to understand this problem, let's start with the InnoDB index data structure and data organization. We all know that when computers store data, they have the smallest storage unit, which is like the smallest u
What is an inverted index?
    Not much to say, go straight to the dry goods!     Welcome everyone, pay attention to WeChat scan code and join my 4 WeChat public accounts:   The pit of big data Java from entry to architect The pit of artificial intelligence Java full stack alliance        There are a lot of learning video materials and wonderful technical articles pushed every day... Life is not easy,
Adaptive hash index of key features of InnoDB
First, the resource consumption analysis of the index 1. Three characteristics of index   1. Small: index only on one or more columns   2. Orderly: can quickly locate the end point   3. There is a tree: the starting point can be located, and the tree height is generally less than or equal to 3 2. The resource consumption point of the index   1. The height of the tree, the data
mysql-------Four index types
The type of index There are four types of mysql indexes:primary key index,unique index,normal indexandfull text index. by giving the fieldadd indexCanImprove data read speed, to improve the concurrency and pressure resistance of the project.Index optimizationAn optimization method in mysql. The index acts ascatalog of books, which can be based on page numbers in the table of c
From distributed consistency to CAP theory and BASE theory
statement of problem In the field of computer science, distributed consistency is a very important and widely explored and demonstrated problem. Let's first look at three business scenarios. 1. Ticket sales at the railway station Suppose our end user is a traveler who often travels by train. Usually, he goes to the ticket office of the station to buy a ticket, then takes the t
MurmurHash3_ The most detailed introduction
Cryptographic hashes and non-cryptographic hashes - MM is a non-cryptographic hash First understand the encrypted hash and non-encrypted hash, Cryptographic hash functions are designed to be secure and collisions are hard to find. That is: a message m with a given hash h is hard to find; i
Detailed explanation of insertion and deletion of B-tree and B+ tree
Introduction: This article mainly introduces the insertion and deletion operations of B-tree and B+ tree. The purpose of writing this blog is to find that there is no relevant blog to introduce the relevant operations of the B+ tree in detail by way of example. Because I am also very confused about some details, I have an epiphany on the operation of the B+ tree by consulting
The height of the b+ tree under the innodb index of mysql.
Introduction to B+ Tree Indexes The essence of the B+ tree index is the implementation of the B+ tree in the database. However, B+ tree index has a feature of high fan-out, so in the database, the height of B+ tree is generally 2 to 3 layers. That is to say, searching for a record of a certain key value only requires at most 2 to 3 IO overheads. Calculated based on 100 IOs per
From B tree, B+ tree, B* tree to R tree
Section 1, B tree, B+ tree, B* tree 1. Foreword: Dynamic search trees mainly include: Binary Search Tree, Balanced Binary Search Tree, Red -Black Tree, B-tree/ B + -tree/ B * - tree  (B~Tree). The first three are typical binary search tree structures, and the search time complexity O (log 2 N ) is related to the depth of the tree, so reducing the depth of the tree will natural