Blog Entries

Measure Linux web server memory usage correctly

Important update: This article was originally posted back in 2014. However, as I later posted in 2017 in the blog post Does your Linux server need a RAM upgrade? Lets check with free, top, vmstat and sar …there was a Linux kernel change to address this in 2016. Hopefully, this change will motivate New Relic and others to follow […]

MySQL Query Cache for Performance, Avoid This When Tuning

Update: MySQL query cache is deprecated as of MySQL 5.7.20, and is removed in MySQL 8.0. – mysql.com One of the most misconfigured MySQL performance features, is MySQL query_cache_size. This post references a web server with 32 gigabytes of RAM where the existing config had MySQL’s query cache size set incorrectly to 4 gigabytes. The thought behind it seemed […]

Finding Linux Compatible Printers

Here’s all the info and links needed to find a printer or all-in-one printer that supports Linux. If you don’t want to spend hours comparing printers, have a look at my recommended Linux compatible printers. Last updated November 5th 2018. This is the promised update as per the comments section below, sorry about the delay! Fixed broken manufacture product […]

Replacing Cloudflare with CSF Firewall

November 5th 2018 update: I’ve updated this article (the install URL and other minor fixes/improvements). I replaced Cloudflare and thus also Cloudflare Argo with KeyCDN + local firewall and server hardening for this blog as of June 2018. However, do support clients who use Cloudflare and still highly recommend it.  2017 update: With the recent Cloudflare “Cloudbleed” data leak. […]

Best Linux Distro 2018, for desktop

Searching for the best Linux distro in 2018 for your desktop computer or laptop? This article will probably be most useful to those who don’t know what /etc/fstab is used for. Also, this post does not cover Linux server distributions, but instead focuses on the best Linux desktop distros (distributions). One great way to increase your familiarity with Linux […]

htop: Here’s how to customize it

htop is an interactive system-monitor, but also a process-viewer, process-manager, strace tool and more. Sysadmins may opt to use htop in cases where Unix top does not provide enough information about system processes. htop uses a cursor-controlled interface for sending signals to processes. Just one example where this comes in handy: you don’t have to type […]

100 Server and Application Performance Monitoring Tools

Last Updated: Oct 11th 2018, 100+ – Fixed 11 broken links. (including defunct, mergers, acquisitions, or changed links) December 1st 2017 update: 70 100 Top Server Monitoring & Application Performance Monitoring Tools. August 6th 2017 update: 50 70 Top Server Monitoring & Application Performance Monitoring Tools. Back in 2014, I compiled a list of the top 20 server performance monitoring solutions. Largely because I […]

How to Kill Inactive SSH Sessions

So, you’ve been disconnected from your server a couple of times which resulted in inactive ssh sessions. You know this because when you use the “w” command, you see something like the following… 22:47:28 up 315 days, 21:09, 2 users, load average: 9.04, 8.17, 7.30 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT root pts/0 ipxxx-xxx-xxx-xxx 23:54 […]

MySQL Performance: Stop hoarding. Drop unused MySQL databases

Last year, I was assisting a new client in addressing MySQL performance issues. There were several areas where MySQL performance issues were addressed. One issue overlooked for several years prior to our communications, was that of keeping around unused databases. Over 15GB of unused MySQL data – a mix of MyISAM and Innodb tables – […]

Linux server performance: Is disk I/O slowing your application?

If your Linux server is bogged down, your first step is often to use the TOP command in terminal to check load averages and wisely so. However, there are times when TOP shows very high load averages even with low cpu ‘us’ (user) and high cpu ‘id’ (idle) percentages. This is the case in the video below, load averages […]