Search results: mysql

Linux Performance: Why You Should Almost Always Add Swap Space

We know that using swap space instead of RAM (memory) can severely slow down the performance of Linux. So then, one might ask, since I have more than enough memory 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 […]

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 […]

PHP 5.6 EOL (End of Life) – PHP 7 Compatibility Check

Summary: PHP 7.3 benchmark, how to check your PHP scripts/apps for PHP 7 compatibility, upgrade to PHP 7 ASAP, confirm OpCache is enabled/monitored and some php.ini optimization tweaks.   PHP 5.6 and PHP 7.0 to hit EOL this year! reached EOL last Year! (2018) PHP 5.6 was first released back in 2014, with alpha 1 released in January 2014. […]

Could not increase number of max_open_files to more than… (Solution)

A quick solution to the warning “Could not increase number of max_open_files to more than” when starting MySQL or MariaDB. For some background read How MySQL Opens and Closes Tables. Here’s an excerpt: “The table_open_cache and max_connections system variables affect the maximum number of files the server keeps open. If you increase one or both of these […]

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 […]

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 […]

Linux top: Here’s how to customize it

The top command – referred to below as Linux top – 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 by Linux top command and the order […]

Free Linux Server Monitoring and APM solutions for SysAdmins

Today’s software applications require developers, testers, and SysAdmins to work together (DevOps) more seamlessly than ever before. A single line of code or poorly configured service can negatively impact your application’s performance, causing crippling slowdowns for end-users. This is where application performance monitoring (APM), comes in. APM is also referred to as application performance measurement or application performance management. […]

How to upgrade to PHP 7 on RHEL/CentOS

TL;DR = Upgrade to PHP 7 using Remi’s RPM repository – PHP Configuration wizard. Red Hat Enterprise Linux (RHEL) is a Linux distribution developed by Red Hat targeted toward the commercial market. Red Hat uses strict trademark rules to restrict free re-distribution of its officially supported versions, but still freely provides its source code. Third-party derivatives […]

Logagent: The Swiss Army Knife for Log Processing?

Guest post by Stefan Thies DevOps Evangelist at Sematext Group Inc. Dealing with log files or extracting data from various data sources is a daily task in the IT administration. Users ask about statistics or details of their technical or business operations. The relevant data is often present in log files, databases or message queues. Converting […]