Resolving MySQL Host Access Denied Error via Permission Bypass
Identifying the Connection IssueWhen setting up a fresh MySQL instance on a test server, connection attempts may fail with the following error:ERROR 1130 (HY000): Host 'node-01' is not allowed to connect to this MySQL serverThis indicates that the server's host-based access control does not permit connections from the specific hostname. Since c ...
Posted on Fri, 24 Jul 2026 16:24:53 +0000 by delmardata
Mastering the sed Stream Editor for System Administration
Overview and Mechanics
The sed (stream editor) is a powerful utility designed for parsing and transforming text streams. Unlike interactive editors, it operates automatically based on scripts or command-line arguments. Internally, sed processes input line by line. Each line is copied into a temporary area known as the Pattern Space. The command ...
Posted on Thu, 23 Jul 2026 16:33:35 +0000 by kokomo310
Redis Installation and Configuration Guide
Firewall Configuration
To allow Redis traffic through the firewall, add a rule for port 6379:
iptables -I INPUT -p tcp --dport 6379 -j ACCEPT
service iptables save
Installation Steps
Navigate to the download directory:
cd /usr/local/src
Download the Redis source package (example version 3.2.9):
wget http://download.redis.io/releases/red ...
Posted on Wed, 22 Jul 2026 16:53:15 +0000 by hyeteck
Real-Time Data Synchronization Using sersync and rsync
1. Confgiure the Slave Server
Install Rsync on the Slave Server
[root@slave ~]# rpm -ivh rsync-3.1.2-11.el7_9.x86_64.rpm
Configure Rsync on the Slave Server
[root@slave ~]# vim /etc/rsyncd.conf
log file=/var/log/rsync.log
pid file=/var/run/rsyncd.pid
[server]
path=/root/test
use chroot=true
max connections=4
read only=no
list=true
uid=root
gi ...
Posted on Wed, 22 Jul 2026 16:08:22 +0000 by Ironmann00
Extract Nginx Logs by Date Range Using sed
When nginx access logs reach gigabyte scale, utilities like cat or tail become impractical for pinpointing traffic on a specific date. The sed stream editor processes text line-by-line using regular expressions, making it efficient for slicing large log files by timestamp ranges.
Log Timestamp Structure
A standard nginx access entry places the ...
Posted on Tue, 21 Jul 2026 17:08:10 +0000 by SUNNY ARSLAN
Essential Linux Command Reference
In Linux, there are several ways to execute commands that continue running even after you close your terminal session:
Background execution with &: The ampersand symbol allows a command to run in the background. However, if you close your terminal (like Xshell), the process will terminate.
nohup command: This allows a command to keep runni ...
Posted on Tue, 21 Jul 2026 16:41:07 +0000 by imstupid
LVS Load Balancing: NAT and DR Mode Implementation
Introduction to LVS
LVS (Linux Virtual Server) is an open-source project initiated by Wensong Zhang, primarily designed to achieve load balancing at the Linux kernel level. It enables the creation of a high-availability, high-performance server cluster by distributing client requests among backend servers according to load balancing algorith ...
Posted on Mon, 20 Jul 2026 17:40:42 +0000 by soulroll
Linux /proc File System Overview
Understanding the /proc Virtual File System
The /proc directory serves as a virtual file system in Linux that provides access to kernel and process information through file-like interfaces. This system acts as a window into the kernel's data structures, allowing users and applications to retrieve system information without making direct system ...
Posted on Mon, 20 Jul 2026 17:02:57 +0000 by Loafin
Implementing While Loops in Bash Shell Scripts
While Loop FundamentalsThe while construct evaluates a condition placed after the while keyword. If the condition evaluates to true, the commands within the loop body execute. After reaching the done statement, control returns to re-evaluate the condition. This cycle continues until the condition becomes false. If the condition is initially fal ...
Posted on Sun, 19 Jul 2026 17:11:49 +0000 by snipe7kills
Files and Directory Management in Linux
1. Linux File Attributes
In Linux systems, file and directory attributes include: inode, type, permission attributes, number of hard links, owner and group, and last modification time.
Execute ls -lhi command to view these attributes:
total 4.0K
24563 drwxr-xr-x 2 root root 4.0K Jun 28 21:30 123
6464 -rw-r--r-- ...
Posted on Sun, 19 Jul 2026 17:03:36 +0000 by amwd07