We share common IT technologies (Java, Web, SQL, etc.) and practical applications of emerging software development techniques. New articles are posted daily. Follow IT Xianyu to stay ahead in tech. The IT Xianyu series is being regularly updated.
This article explains how Java developers can replace thousands of individual UPDATE statements with a single PostgreSQL stored procedure call, covering the motivation, procedure creation, Java invocation, scheduling with shell scripts, performance benchmarks, and common pitfalls.
This article explains why Redis is becoming a DBA's favorite, provides a five‑minute installation guide, essential commands, cache‑design pitfalls and solutions, explores Redis data structures with Java examples, demonstrates distributed locking and flash‑sale implementations, and covers clustering, backup, monitoring, and performance tuning.
After CentOS 7 reaches end‑of‑life on June 30 2024, this guide explains why you must migrate, outlines three essential pre‑migration preparations, and provides detailed step‑by‑step commands to upgrade first to AlmaLinux 8 and then to AlmaLinux 9, including post‑migration checks and common pitfalls.
This tutorial explains why DBAs need security hardening and log analysis, shows how to configure minimal‑privilege roles and precise permissions in PostgreSQL, demonstrates how to detect and revoke redundant privileges, and provides a step‑by‑step guide to installing and using pgBadger for log analysis and automated reporting.
This guide walks through preparing two CentOS 7.9 servers, installing Docker and Kubernetes 1.19 components, initializing a master node, joining a worker node, and validating the cluster with a sample Nginx deployment, including common troubleshooting tips.
This guide explains why the default CentOS 7 YUM repositories are slow for Chinese users and provides step‑by‑step instructions—including backing up existing .repo files, downloading Alibaba Cloud mirrors, adjusting version numbers, refreshing the cache, verifying updates, troubleshooting common errors, and advanced tips such as adding EPEL—so you can achieve faster, more reliable package management.
This article provides a detailed, step‑by‑step tutorial on using Linux commands such as top, grep, awk, and bash scripts for performance bottleneck detection, memory‑leak investigation, automated alerts, efficient Vim editing, permission matrix configuration, multi‑condition log analysis, and quick troubleshooting in a library management environment.
This tutorial walks through preparing the Linux environment, installing MySQL 5.7, configuring master and slave servers, creating replication users, verifying synchronization, troubleshooting common issues, and applying advanced options such as GTID and semi‑synchronous replication, all with complete command examples.
This article provides a thorough tutorial on SQL fundamentals, including statement order, core clause rules, templates for SELECT/INSERT/UPDATE/DELETE, practical multi‑table query cases, join and subquery techniques, common pitfalls, index optimization strategies, experimental performance data, and a structured learning path for mastering database development.
This article presents a Bash script that automates full MySQL database backups, supports configurable connection parameters, backup storage paths, retention policies, logs operations, and can be scheduled via cron, providing a comprehensive solution for reliable database backup and cleanup.
