Programmer Think

HDFS transparent encryption, Keystore and Hadoop KMS, encryption area The data in HDFS will be saved in the form of blocks in the local disk of each data node, but these blocks are in clear text. If you directly access the directory where the block is located under the operating system, you can directly view the contents through the cat comman ...

Local operation mode Basic introduction Spark's Local operation mode is also called Local operation mode and pseudo distributed mode. This is called Local mode because all spark processes in this mode run in the virtual machine of a Local machine without any resource manager. It mainly uses multiple threads of a single machine to simulate spa ...

Distributed architecture infrastructure: detailed explanation of Java RMI Introduction to RMI Java RMI, remote method call( Remote Method Invocation ), a method for implementing remote procedure calls (RPCs) (Remote procedure call) Java API, which can directly transfer serialized Java objects and Distributed garbage collection . Its implemen ...

Foreword Backtracking is a mindless rush. After hitting a wall, you retreat and continue to do it. It belongs to a kind of violent problem-solving idea; In fact, the same is true. When we encounter some classified problems and can't think of a more sophisticated solution, we first consider violence, enumerate all situations, and then deal wit ...

PostgreSQL is the most open source database like oracle. We can compare Oracle and learn its architecture, which is easier to understand. The main structure of PostgreSQL is as follows: 1. Storage structure PG data storage structure is divided into logical storage structure and physical storage structure. Among them: logical storage structur ...

This article introduces an important role in microservices: gateway. As for how to select a gateway, Alibaba has not yet selected a gateway. Of course, it has chosen Spring cloud Gateway. After all, it is my son. The article contents are as follows: Why do I need a gateway? In the traditional monomer architecture, only one service is ope ...

What is the reflection mechanism Reflection mechanism is to know all the properties and methods of any class in the running state; For any object, you can call any of its methods and properties; This kind of dynamically acquired information and the function of dynamically calling object methods are called the reflection mechanism of java langu ...

1 Introduction redis does not officially provide the installation package under windows. The windows installation package you see is the version officially maintained by Microsoft. Why Microsoft doesn't officially provide the installation package of windows version: I guess so: because redis is single threaded and high-performance. Therefo ...

Software design - Preliminary Thinking on Modular Design II Book connection We have The Sender interface is designed to realize the sending of information. Therefore, we have made two implementation classes, mailbox sending and SMS sending. (implemented class, not implemented function) The Verify interface is designed to implement differe ...

Java 12 does not have many useful features for developers, but it is practical.   String enhancement Java 12 further enhances string operations by adding two methods. String indent String indent(int n) indents the string according to parameter n. The specific rules are When n > 0, n spaces will be inserted at the beginning of each line ...