Software preparation I am using a virtual machine with CentOS-6.6, with the host name repo. Refer to the steps to install a Linux virtual machine in Windows, I installed JDK in that virtual machine, refer to the guide to installing JDK in Linux. In addition, the virtual machine is configured with a key-free login itself, and the settings for configuring key-free login between each virtual machine are referenced. The download address of Hadoop installation package is: https://mirrors.aliyun.com/apache/hadoop/common/. I am using hadoop 2.6.5 version. Upload the Hadoop installation package to the server and unzip [root@repo~]#tarzxv

1. The Origin of .NETCore When talking about .NETCore, we must not mention its predecessor .NET. Java was in the limelight at that time, and Microsoft also favored Java. The Java virtual machine on the Windows platform was developed by Microsoft based on JVM standards. It is said to be the best performance Java virtual machine at that time. However, Microsoft has its own little abacus, trying to bundle Java with the Windows platform and add some Windows-specific features. Sun's dissatisfaction with this led to a breakdown of the relationship between the two parties, and Microsoft then launched .NET. .NET has borrowed many features of Java since its inception and gradually surpassed Java in language features and form development. Java in version 1.6

Integrating Postman applications on CentOS can be achieved through a variety of methods. The following are the detailed steps and suggestions: Install Postman by downloading the installation package to download Postman's Linux version installation package: Visit Postman's official website and select the version suitable for Linux to download. Unzip the installation package: Use the following command to unzip the installation package to the specified directory, for example /opt: sudotar-xzfpostman-linux-x64-xx.xx.xx.tar.gz-C/opt Please note that "postman-linux-x64-xx.xx.xx.tar.gz" is replaced by the file name you actually downloaded. Create symbols

NGINX and Apache each have their own advantages and disadvantages, and the choice should be based on specific needs. 1.NGINX is suitable for high concurrency scenarios because of its asynchronous non-blocking architecture. 2. Apache is suitable for low-concurrency scenarios that require complex configurations, because of its modular design.

PHP code can be executed in many ways: 1. Use the command line to directly enter the "php file name" to execute the script; 2. Put the file into the document root directory and access it through the browser through the web server; 3. Run it in the IDE and use the built-in debugging tool; 4. Use the online PHP sandbox or code execution platform for testing.

Understanding Nginx's configuration file path and initial settings is very important because it is the first step in optimizing and managing a web server. 1) The configuration file path is usually /etc/nginx/nginx.conf. The syntax can be found and tested using the nginx-t command. 2) The initial settings include global settings (such as user, worker_processes) and HTTP settings (such as include, log_format). These settings allow customization and extension according to requirements. Incorrect configuration may lead to performance issues and security vulnerabilities.

Optimizing the performance of Hadoop distributed file system (HDFS) on CentOS systems can be achieved through a variety of methods, including adjusting system kernel parameters, optimizing HDFS configuration files, and improving hardware resources. The following are detailed optimization steps and suggestions: Adjust the system kernel parameters to increase the limit on the number of files opened by a single process: Use the ulimit-n65535 command to temporarily adjust. If it needs to take effect permanently, please edit the /etc/security/limits.conf and /etc/pam.d/login files. Optimize TCP parameters: Edit /etc/sysctl.conf file, add or modify the following content: net.ipv4.tcp_tw

When configuring Nginx on Debian system, the following are some practical tips: The basic structure of the configuration file global settings: Define behavioral parameters that affect the entire Nginx service, such as the number of worker threads and the permissions of running users. Event handling part: Deciding how Nginx deals with network connections is a key configuration for improving performance. HTTP service part: contains a large number of settings related to HTTP service, and can embed multiple servers and location blocks. Core configuration options worker_connections: Define the maximum number of connections that each worker thread can handle, usually set to 1024. multi_accept: Activate the multi-connection reception mode and enhance the ability of concurrent processing. s