Author: Rahul

MySQL replication is a process where a master server replicates its data to one or more slave servers. This can provide several benefits such as increased data availability, improved performance, and easier backups. One important aspect of replication is security, and in this article, we will explore how to configure MySQL master-slave replication with authentication using SSL certificates. By using SSL certificates, we can ensure that the data being replicated is secure and can only be accessed by authorized parties. Additionally, SSL certificates can also be used to authenticate the master and slave servers, providing an additional layer of security.…

As a programmer or developer, it’s common to encounter files with empty lines that need to be removed for better readability and code organization. While manually removing empty lines can be a tedious and time-consuming task, there are several techniques and tools available to streamline the process. In this article, we’ll explore the most effective ways to delete empty lines from files, making your file editing process faster and more efficient. Delete Empty Lines from a File Command-line tools are a powerful and flexible solution for automating file editing tasks. To remove empty lines using command-line tools, you can use…

Debugging is the process of finding and resolving bugs within a computer program. It provides a huge output at the runtime to analyze each part of the execution. Which helps to identify the root cause of any error in the script. In this tutorial, you will learn how to Debug a shell script on the Linux command line. We can debug a shell script in two ways. Either add the debugging instruction in the shell script by using “set -xv” or using -xv on command line while executing script. Adding Debug Instructions in Shell Script Let’s create a small script…

MAC-based filtering is useful for networks using DHCP to assign IP addresses to systems. As we know MAC is hard coded on NIC and can’t be changed but IP addresses assigned by DHCP may change on next IP assignment. This tutorial will help you to how to Configure Squid Proxy Server Mac Address Based Filtering. If you do not have Squid installed, Go to below link for installing squid on CentOS/RHEL/Fedora systems. Install and Configure SQUID Proxy Server on CentOS/RHEL Linux ACL rules are need to add in squid configuration file /etc/squid/squid.conf. Remember that squid Squid always applied first matching…

Squid is the most popular Proxy server for Linux systems. The squid proxy server is also useful for the web packet filtering. Most of the web hosting providers use the Squid proxy for caching the repetitive data to increase website speed. This article will help you to Install and Configure SQUID Proxy Server on CentOS, Redhat and Fedora Linux systems. Step 1 – Install Squid Squid packages are available in default yum repositories. Execute below command on your server to install SQUID proxy server. sudo yum install squid # On CentOS/RedHat Systems sudo dnf install squid # On Fedora Systems…

Openfire is a real time collaboration server. It uses XMPP protocol for instant messaging. This tutorial will help you to install and configure your won instant messaging server using Openfire and Spark. You can configure it to use in your LAN as well as over internet also. Step 1 – Prerequisites Before installing Openfire make sure you have java installed on your system. If you do not have Java installed use following tutorials to install Java on your system. How to Install Oracle JAVA 8 on Debian How to Install Oracle JAVA 8 on Ubuntu & LinuxMint How to Install…

Varnish is an Web accelerator used for content-heavy dynamic web sites. Its used as front-end caching server for web servers. This tutorial will help you to setup Varnish on your System. Step 1: Add Atomic Repository There are latest release available in Atomic repository in RPM format. For RHEL/CentOS 5: # rpm -Uvh http://www6.atomicorp.com/channels/atomic/centos/5EL/i386/RPMS/atomic-release-1.0-16.el5.art.noarch.rpm For RHEL/CentOS 6: # rpm -Uvh http://www6.atomicorp.com/channels/atomic/centos/6/i386/RPMS/atomic-release-1.0-16.el6.art.noarch.rpm Step 2: Install Apache and Configure Use following commands to install Apache on your system. # yum install httpd Configure Apache to work on port 82. Edit Apache configuration file /etc/httpd/conf/httpd.conf and change value of Listen from 80 to…

OpenSSH is a widely used software suite for secure remote access to systems and servers over the internet. It provides an encrypted communication channel between two systems, preventing unauthorized access and eavesdropping. However, relying solely on a password for authentication can leave your system vulnerable to brute-force attacks and password guessing. Two-factor authentication (2FA) provides an extra layer of security to OpenSSH by requiring users to provide an additional piece of information, usually a one-time code generated by a mobile app, in addition to their password. In this article, we will explore how to set up OpenSSH with two-factor authentication…

Issue: Today, I found that /tmp was showing 100% full but, After deleting all files from /tmp it was still showing full. After google it, I found that there are some file which deleted from /tmp folder but still used by process used all space. Generally these files used by apache or mysql. Use following command to check files # lsof | grep /tmp mysqld 3236 mysql 6u REG 202,5 0 2373 /tmp/ibZzBzJ8 (deleted) mysqld 3236 mysql 7u REG 202,5 0 2378 /tmp/ibfoQY3a (deleted) mysqld 3236 mysql 11u REG 202,5 0 2393 /tmp/ibz2IDcI (deleted) mysqld 3236 mysql 220u REG 202,5…

Error: Below issue generally comes with database incompatibilities with the current version of MySQL. It may happen due to MySQL server upgrade or downgrade. Error in query (1548): Cannot load from mysql.proc. The table is probably corrupted Solution: This issue may resolve by repairing mysql databse using following command. # mysqlcheck -r mysql proc -u root -p Enter password: mysql.proc OK In case you are still getting same error while accessing proc table, You need to execute mysql_upgrade command to fix issue. Read more about mysql_upgrade # mysql_upgrade -u root -p