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Posts by Joss Malasuk for Linux:
How to increase the open file limit for the tomcat service on Systemd based systems such as Red Hat 7 and CentOS 7.
This simple bash one liner will show you how to find the number of requests Apache or Nginx has served per hour on a specified date. This information will allow you to quickly determine a spike in traffic or possible attack on a server.
In this article, we will take an in-depth look at how to install, secure, optimize, and monitor the Memcached object caching system.
There are numerous compression tools available to Linux and Database administrators including gzip, xz, bzip2, and pigz and others. Gzip has been the classic go to for compression, however there has been a move to xz over gzip due to improvements in compression. This quick guide will show the differences in compression and time to complete specifically when dealing with mysqldump. When dumping databases, it is often a balance between total achieved compression and time it take to complete, to keep lock time to a minimal.
Ever worked on a MySQL having table locking problems and when you run 'show full processlist' your screen is blasted with hundreds of lines of queries? MySQL have a feature to help you parse this information easier with a feature known as a 'pager'
Recently I can across the ability to run Linux commands in the MySQL shell without the need to drop out of the MySQL shell. This can save quite some time in the long run when troubleshooting database performance issues as you do not need to switch shells to run commands.
Auditd is a user-space component of Linux auditing subsystem that collects and logs messages sent by the kernel. This tool can be used to collect critical security information so you can ensure you know what is happening on your systems. Auditd does not provide any form of additional security, however it does provide insights and audit trails regarding what is done on a server. Not only is this information useful in troubleshooting, it also allows certification of many compliance guides.
Intrusion Detection Systems monitor devices or networks for malicious activity or policy violations. AIDE, or Advanced Intrusion Detection Environment, allows systems administrators the ability to keep an eye on files and detect when a file is created, modified, or altered in any way. AIDE can be used to let you know when a malicious file has been uploaded to your application, or when a script has been injected with malicious code. If can be used to identify nearly any change you can imagine to your system.
When reviewing access logs on servers, you may find yourself wondering, where in the world is this IP address from? After being asked this hundreds of times, a coworker started building a API in python to return the geographic location of an IP address. This API, now called wherediz? is a script friendly way to find the location of an IP address.
On high traffic web servers, its important to ensure that your services are configured to maximize, or limit, the amount of resources that are used. In this post we will talk about Nginx's worker settings, and what they mean.