.IO TLD DNS issues and a day without Cloudflare

Yesterday morning, I started receiving down alerts for this blog. Pingdom’s alerts include the message: “Reason: Non-recoverable failure in name resolution”. Right from the start, to simplify troubleshooting, I wrongly removed Cloudflare since I had a similar issue with them a year ago and was able to resolve by temporarily removing. However, upon investigation the issue […]

PHP memory_limit – understanding and increasing this setting

PHP memory_limit is per-script, just as a highway speed limit is per-vehicle. What happens when a web host blames PHP memory_limit setting for memory usage issues on a Linux web server. For example, although PHP’s memory limit may be set high to 1GB, that does not mean that scripts will pile up in use to […]

Linux top: Here’s how to customize it

The top program provides a dynamic real-time view of a running system. It can display system summary information as well as a list of processes or threads currently being managed by the Linux kernel. The types of system summary information shown and the types, order and size of information displayed for processes are all user […]

Using CentOS CR (Continuous Release) Repo

CentOS (Community Enterprise Operating System) is a Linux distribution that attempts to provide free, enterprise-class, community-supported computing platform functionally compatible with its upstream source, Red Hat Enterprise Linux (RHEL). CentOS is run by volunteers who work directly with Red Hat’s RPM source files and pushing them to CentOS for release. At times the project will fall behind […]

Strip Down Apache to Improve Performance & Memory Efficiency

Can you believe that its been 5 years since the release of Apache 2.4?! Still, most Apache based web servers continue to run Apache version 2.2 or even 2.0. This is understandable for the same reasons why Apache web servers are still used more than Nginx… compatibility, official support and features. If you haven’t replaced Apache […]

PHP performance: oPcache Control Panels

OPcache is a PHP extension which improves PHP performance by storing precompiled script bytecode in shared memory, thereby removing the need for PHP to load and parse scripts on each request. The extension is built-in for PHP 5.5+ …but, if you are looking to improve PHP performance, the first step should be to use PHP 7+ which […]

Linux Performance: Why You Should Almost Always Add Swap Space

We know that using swap space instead of RAM can severely slow down the performance of Linux. So then, one might ask, since I have more than enough RAM available, wouldn’t it better to remove swap space completely? The short answer is, No. There are performance benefits when swap is enabled, even when you have more than enough […]

MySQL Performance Tuning: Tips, Scripts and Tools

With MySQL, common configuration mistakes can cause serious performance problems. In fact, if you mis-configure just one of the many config parameters, it can cripple performance! (see examples) Of course, the performance of MySQL is often tied greatly to the efficiency of your MySQL queries. It’s important to ensure that your performance issues are not […]