A Content Delivery Network (CDN) is a system of distributed servers located around the world that work together to deliver web content to users more efficiently.

The main goal of a CDN is to reduce latency and improve the speed, reliability, and security of content delivery. Instead of serving content from a single origin server, a CDN caches and delivers static assets (like images, stylesheets, scripts, and videos) from servers that are geographically closer to the user.

When a user accesses a website:

• The CDN determines the closest edge server to the user.
• Static content is served from that nearby server.
• This reduces the time it takes for the content to load and minimizes bandwidth usage on the origin server.

• Faster load times for users worldwide
• Reduced server load and bandwidth usage
• Improved availability during traffic spikes
• Enhanced security features like DDoS protection and secure SSL delivery

If your website is hosted in Germany and a visitor from Japan accesses it, the CDN will serve cached content from a server in Japan, making the site load much faster for that user.

• Cloudflare
• Akamai
• Fastly
• BunnyCDN
• Amazon CloudFront

Second Life uses a Content Delivery Network (CDN) to distribute texture and mesh data more efficiently across the globe. This shift from simulator-based delivery to CDN-based delivery has brought several key improvements to the platform.

• Faster loading of textures and meshes Assets like avatar skins, clothing, and environment textures now load significantly faster, especially in crowded regions. • Quicker region crossings and teleports Reduced load on simulator servers means smoother transitions between areas. • Reduced “fuzzy” or “cloudy” avatars Avatars appear fully rendered more quickly, improving visual quality and immersion.

• CDN offloads asset delivery from simulator servers, freeing up resources for physics, scripting, and interaction.
• High HTTP load conditions on servers have dropped dramatically since the CDN rollout.

• Users outside North America benefit even more, with over 50% faster download times for textures and meshes. • CDN edge servers deliver content from locations closer to the user, reducing latency.

• Improved resilience during traffic spikes or outages. • Faster recovery from load-related issues thanks to CDN redundancy and optimizations.

The integration of CDN technology into Second Life has: • Enhanced user experience through faster asset loading • Reduced strain on core infrastructure • Enabled more scalable and reliable virtual environments

This guide explains how to monitor Squid proxy logs in real time, edit its configuration file, and includes a sample shell script for setting up a test directory.

To monitor Squid activity in real time, use the following command:

sudo tail -f /var/log/squid/access.log /var/log/squid/cache.log

This will continuously display new entries from: • access.log – records client requests • cache.log – logs cache behavior and errors

To edit Squid’s main configuration file, run:

sudo nano /etc/squid/squid.conf

Example config:

http_port 192.168.0.43:1234 #the machine this is running on
# http_port 127.0.0.1:1234

cache_dir aufs /var/spool/squid/slcdn-cache 100000 16 256
cache_mem 1024 MB
maximum_object_size 1024 MB
maximum_object_size_in_memory 50 MB
minimum_object_size 0 KB

cache_log /var/log/squid/cache.log
access_log daemon:/var/log/squid/access.log
cache_store_log /var/log/squid/store.log

acl localnet src 192.168.0.0/24
http_access allow localnet
http_access deny all

cache allow all
refresh_pattern . 43200 100% 43200

range_offset_limit -1
collapsed_forwarding on

Inside , you can define the paths for Squid’s log files:

• : logs cache-related events • : logs client access (via daemon) • : logs stored objects

Here’s a simple Bash script to create a test directory:

tTo run the script run the command:

./SLEdgeCDN.sh

SLEdgeCDN.sh

#!/bin/bash
set -e
 
BASE="$HOME/Desktop/SL_CDN_TEST"
 
echo "=== SL CDN Installer ==="
 
# install squid if not installed
if ! command -v squid >/dev/null 2>&1; then
  if [ -f /etc/debian_version ]; then
    sudo apt update && sudo apt install -y squid
  elif [ -f /etc/fedora-release ]; then
    sudo dnf install -y squid
  elif [ -f /etc/arch-release ]; then
    sudo pacman -Sy --noconfirm squid
  else
    echo "Your distro isn’t supported. Install squid manually."
    exit 1
  fi
fi
 
# backup old squid.conf
sudo cp /etc/squid/squid.conf /etc/squid/squid.conf.bak.$(date +%s) || true
 
# write new config
sudo tee /etc/squid/squid.conf >/dev/null <<EOF
http_port 127.0.0.1:1234
 
cache_dir aufs /var/spool/squid/slcdn-cache 100000 16 256
cache_mem 1024 MB
maximum_object_size 1024 MB
maximum_object_size_in_memory 50 MB
minimum_object_size 0 KB
 
cache_log /var/log/squid/cache.log
access_log daemon:/var/log/squid/access.log
cache_store_log /var/log/squid/store.log
 
acl localnet src 127.0.0.1/32
http_access allow localnet
http_access deny all
 
cache allow all
refresh_pattern . 43200 100% 43200
 
range_offset_limit -1
collapsed_forwarding on
EOF
 
# make cache and log dirs
sudo mkdir -p /var/spool/squid/slcdn-cache /var/log/squid
sudo chown -R proxy:proxy /var/spool/squid /var/log/squid
sudo squid -z
 
# restart squid
sudo systemctl restart squid
 
# reset desktop control folder
rm -rf "$BASE"
mkdir -p "$BASE"
 
# main control script
cat > "$BASE/slcdn.sh" <<'EOS'
#!/bin/bash
LOG=$HOME/Desktop/SL_CDN_TEST/proxy.log
start()   { echo "Starting Squid..." | tee -a "$LOG"; sudo systemctl start squid; }
stop()    { echo "Stopping Squid..." | tee -a "$LOG"; sudo systemctl stop squid; sudo killall -9 squid 2>/dev/null || true; sudo rm -f /run/squid.pid; }
restart() { echo "Restarting Squid..." | tee -a "$LOG"; stop; sudo squid -z || true; start; }
status()  { echo "Squid status:" | tee -a "$LOG"; sudo systemctl status squid --no-pager -l; }
case "$1" in start|stop|restart|status) "$1";; *) echo "Usage: $0 {start|stop|restart|status}";; esac
EOS
chmod +x "$BASE/slcdn.sh"
 
# clear cache script
cat > "$BASE/slcdn-clear.sh" <<'EOS'
#!/bin/bash
echo "Clearing Squid cache..."
sudo systemctl stop squid || true
sudo killall -9 squid 2>/dev/null || true
sudo rm -f /run/squid.pid
sudo rm -rf /var/spool/squid/slcdn-cache
sudo mkdir -p /var/spool/squid/slcdn-cache
sudo chown -R proxy:proxy /var/spool/squid/slcdn-cache
sudo squid -z
echo "Cache cleared. Restart Squid to refill."
EOS
chmod +x "$BASE/slcdn-clear.sh"
 
# desktop shortcuts
make_launcher () {
  local name="$1" cmd="$2" term="$3"
  cat > "$BASE/SLCDN-$name.desktop" <<EOD
[Desktop Entry]
Name=SL CDN $name
Exec=$cmd
Icon=utilities-terminal
Terminal=$term
Type=Application
EOD
  chmod +x "$BASE/SLCDN-$name.desktop"
}
 
make_launcher "Start"   "$BASE/slcdn.sh start" true
make_launcher "Stop"    "$BASE/slcdn.sh stop" true
make_launcher "Restart" "$BASE/slcdn.sh restart" true
make_launcher "Status"  "$BASE/slcdn.sh status" true
make_launcher "Clear"   "$BASE/slcdn-clear.sh" true
make_launcher "Cache"   "xdg-open /var/spool/squid/slcdn-cache" false
make_launcher "Debug"   "gnome-terminal -- bash -c \"sudo tail -f /var/log/squid/access.log\"" false
 
echo "Done. Set Firestorm proxy to 127.0.0.1 port 1234"

This script creates a folder on the user’s desktop and can be extended for further setup tasks.