François Schiettecatte fschiettecatte

Django Connections Errors

For a long time I have been running into problems with Django connection errors when running a database query after a long idle period. This does not affect website per-se because connections last a very short time but for batch processes where there is a long interval between database access, Django does not detect that database has dropped the connection and raises an error.

Which really should not be happening because my database connection settings includes:

    'CONN_MAX_AGE': 3500,                   # 3500 seconds because wait_timeout = 3600 in my.cnf

Automatically Setting and Switching Light / Dark Mode in Bootstrap

Bootstrap 5.3.0 introducted the concept of a theme to set the color mode of a website, ostensibly support light color mode and dark color mode.

The examples on the Bootstrap website show how to manually switch between modes but I wanted a way to automatically set the mode based on the operating system setting when the site loaded, and automatically switch the mode when the operating system switched from one mode to another.

So I put together an anonymous function which does the first and a window watcher which does the second.

This JavaScript should be included in the page itself, putting it in a separate file will cause the page to visibly switch modes when it is loaded which is pretty ugly.

Setting up Samba for Linux / MacOS

I recently switched from using Netatalk to Samba for file access from MacOS to linux.

Obviously the Samba is a great resource, on the Samba Wiki the Configure Samba to Work Better with Mac OS X was invaluable for setting up the /etc/samba/smb.conf file, and the vfs fruit man page contains documentation for all the options.

Here is the /etc/samba/smb.conf file I use:

[global]

Removing all traces of a file from a GIT repository

I recently had to remove all traces of a file from a GIT repository.

First clone the repository:

git clone ssh://[email protected]/home/repositories/codebase codebase

High Traffic Server Settings on RHEL / AlmaLinux / Rocky / EuroLinux / CentOS 8

I recently did some work to optimize the network configuration of an AlmaLinux 8 based web server that receives a lot of traffic.

Of course these settings also apply to RHEL / Rocky / EuroLinux / CentOS 8 (hereafter referred to as Linux 8.) I think these should also work on RHEL / AlmaLinux / Rocky / EuroLinux 9 as well but I have not yet tested them.

There is a lot of information on the web for this and it distills down to a minimum recommended configuration, and a recommended configuration.

The minimum recommended configuration should be sufficient for servers with less than 10Gb, and the recommended configuration should be sufficient for servers with 10Gb or more.

	#
	# MPM Event Module
	#
	# Large - 16 CPU / 32GB RAM
	#
	# https://httpd.apache.org/docs/2.4/mod/worker.html
	# https://httpd.apache.org/docs/2.4/mod/event.html
	#
	# Matching WSGI Module Configuration
	# WSGIDaemonProcess @@@@@ processes=20 threads=3 display-name=%{GROUP}

	#
	# MPM Event Module Configuration for Medium Servers
	#
	# Medium - 4 CPU / 16GB RAM
	#
	# https://httpd.apache.org/docs/2.4/mod/worker.html
	# https://httpd.apache.org/docs/2.4/mod/event.html
	#
	# Matching WSGI Module Configuration
	# WSGIDaemonProcess @@@@@ processes=8 threads=3 display-name=%{GROUP}

	#
	# MPM Event Module Configuration for Small Servers
	#
	# Small - 4 CPU / 8-16GB RAM
	#
	# https://httpd.apache.org/docs/2.4/mod/worker.html
	# https://httpd.apache.org/docs/2.4/mod/event.html
	#

	<IfModule mpm_event_module>

	#!/usr/bin/env python3
	# -- coding: utf-8 --

	#--------------------------------------------------------------------------
	#
	# Author: Francois Schiettecatte (FS Consulting LLC.)
	# Creation Date: October 10, 2020
	#

	#!/usr/bin/env python3
	# -- coding: utf-8 --

	#--------------------------------------------------------------------------
	#
	# Author: Francois Schiettecatte (FS Consulting LLC.)
	# Creation Date: October 10, 2020
	#