Tag Archives: sysadmins

‘Clean’ upgrade to PHP 7.* (CentOS / Debian / Ubuntu)

Earlier this year, I wrote a short article: 80% of the web powered by PHP. Also, in the article it was noted that more than 90% of PHP based websites are still using PHP 5. This remains true today. It must be said however, in the past 6 months, there’s been more upgrades to PHP 5.6 […]

Monitoring PHP Performance and Diagnosing Bottlenecks

Last week, we took a quick look at PHP-FPM, reducing process manager (PM) overhead and maxing out PHP-FPM’s throughput by attempting to keep processes in-memory using pm.static. However, beyond development server benchmarks, on our production servers, we also want to drill down into all services and components called up by each user’s interaction. This allows us the opportunity to diagnose PHP and other […]

PHP-FPM tuning: Using ‘pm static’ for max performance

Lets take a very quick look at how best to setup PHP-FPM for high throughput, low latency and a more stable use of CPU and memory. By default, most setups have PHP-FPM’s PM (process manager) string set to dynamic and there’s also the common advice to use ondemand if you suffer from available memory issues. However, lets compare the two management […]

PHP Benchmarks: OPcache vs OPcache w/ Performance Tweaks

A few weeks ago I wrote a short article which highlighted GUI solutions for monitoring and controlling PHP OPcache. We all know that enabling PHP OPcache provides massive performances gains (see benchmark graph at the end of article). In addition, since PHP 5.5, OPcache is now enabled by default. With these facts in mind, is it possible […]

htop and top alternatives

We’ve covered top, atop and indirectly due to it’s popularity as top’s alternative… htop (the last screenshot on this page).  But are there any other htop alternatives worth looking at? This is largely a matter of preference regarding what data is most important to you as it pertains to system health and performance. Although somewhat standard, we […]

.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 […]

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 […]

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 […]