UPDATE: 50 Top Server Monitoring & Application Performance Monitoring (APM) Solutions Last Updated: Nov 23th 2018 – Fixed broken links. (including defunct, mergers, acquisitions, or changed links) Back in September I wrote about an article than touched on the subject of server performance monitoring. Then just last month a LinkedIn connection asked: “I am using New Relic to monitor […]
Measure Linux web server memory usage correctly
November 11, 2018 by Hayden James, in Blog LinuxImportant 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
November 7, 2018 by Hayden James, in Blog LinuxUpdate: 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 […]
Replacing Cloudflare with CSF Firewall
November 5, 2018 by Hayden James, in Blog LinuxNovember 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. […]
htop: Here’s how to customize it
October 17, 2018 by Hayden James, in Blog Linuxhtop 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 […]
How to Kill Inactive SSH Sessions
October 9, 2018 by Hayden James, in Blog LinuxSo, 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
October 4, 2018 by Hayden James, in Blog LinuxLast 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 – […]
How to fix: At least xMB more space needed on the /boot filesystem
August 13, 2018 by Hayden James, in Blog LinuxUpdated: Aug 13th 2018 List all installed kernel packages with: yum list kernel The kernel in-use will be underlined and cannot be removed: Now to remove unused kernels, install the yum-utils package and use the package-cleanup util: yum install yum-utils package-cleanup –oldkernels –count=2 To make this permanent, edit /etc/yum.conf and add the following line: installonly_limit=2 – – – – – […]
Linux: ncdu and mc to manage large directories
August 13, 2018 by Hayden James, in Blog LinuxCreating, modifying and deleting files are common tasks performed in any operating system. Even more so by Sysadmins, Developers and Programmers. For the most part, these tasks are fast enough when managing a handful of files. However, on Linux and especially with servers, you may at sometime have to manage millions or even billions of […]
81% of all Smartphones are powered by Linux
July 19, 2018 by Hayden James, in Blog LinuxUpdate July 19th 2018: Now 85% as per latest report. No, I didn’t use a misleading blog title. Smartphones powered by Linux are in fact dominating the smartphone market. A few of you may be scratching your heads at this point (stop that, you’ll go bald) while others are filled with that Sound of Music […]