Performance

🎄 Intro After a very interesting and fun SUSE hackweek, as every December since some years, I took part to Advent of Code. First of all, I wish to thank Eric Wastl because he’s giving us every year a great and unforgettable advent-ure. [image source: Reddit u/edo360 ] ✨ What’s Advent of Code ? More than just a countdown to Christmas, AoC is a joyful game that invites developers of all age and levels to sharpen their problem-solving abilities and coding skills. Like a virtual advent calendar, AoC presents a new programming puzzle each day from December 1st to 25th. These puzzles are often deceptively simple at first glance, but they quickly unfold into intricate challenges requiring clever algorithms and efficient code. ...

Once in a while I like to play with Advent Of Code problems 🎄. Today I decided to tackle an easy one and, since the answer was almost trivial to find, I wanted to go deeper and understand how to measure and improve the performance of the solution. ...

intro Resource isolation is an hot topic these days, and it’s a problem excellently solved by containerization. However, we can achieve isolation between internal tasks of an operating system by leveraging a technology exposed by the kernel: cgroups. This component is also used by Docker, and other Linux container technologies. Cgroups are the Linux way of organizing groups of processes: roughly speaking a cgroup is to a process what a process is to a thread: one can have many threads belonging to the same process, and in the same way one can join many processes inside the same cgroup. ...

the Apache module mod_status is very useful for inspecting your running webserver, but it gives you only realtime informations about workers, connections, and so on. I wanted a way to keep this data and then be able to do comparison, charts and more useful reports. The first step was configuring mod_status in order to be only accessible from localhost: andrea@myserver:~$ cat /etc/apache2/mods-enabled/status.conf <IfModule mod_status.c> # # Allow server status reports generated by mod_status, # with the URL of http://servername/server-status # Uncomment and change the "192.0.2.0/24" to allow access from other hosts. # <Location /server-status> SetHandler server-status Order deny,allow Deny from all Allow from 127.0.0.1 ::1 # Allow from 192.0.2.0/24 </Location> # Keep track of extended status information for each request ExtendedStatus On # Determine if mod_status displays the first 63 characters of a request or # the last 63, assuming the request itself is greater than 63 chars. # Default: Off #SeeRequestTail On <IfModule mod_proxy.c> # Show Proxy LoadBalancer status in mod_status ProxyStatus On </IfModule> </IfModule> now a little shell script to grab the status page together with other useful informations… ...