Zsync

Zsync based Delta Updates

Is it actually working?

We have been asked why we prefer soar update over appimageupdatetool or zsync

1. The statment here is misleading: https://github.com/AppImageCommunity/AppImageUpdate/blob/d08e085cc6d40bcda85c4ff4ff275a0b0ce444cc/README.md?plain=1#L39

2. In our testing, we found almost all appimages that have zsync updateinfo embedded, use the full bandwidth regardless

3. Soar Update is not only better, but actually checks for version prior to wasting any bandwidth along with comparing Checksums

4. Below, you can verify it yourself

• Install VNStat from your distro, or from source or just use Soar

• Run vnstatd (Terminal: 1, Keep it Running)

Applies only if you didn't install it systemwide & used soar

#Get the Default Config
curl -qfsSL "https://raw.githubusercontent.com/vergoh/vnstat/master/cfg/vnstat.conf" -o "./vnstat.conf"

#Run this in a terminal, call it Terminal 1
sudo "$(which vnstatd)" --alwaysadd --nodaemon --sync --config "./vnstat.conf"

vnstatd running in Terminal 1

• Monitor Live Traffic (Terminal: 2, Keep it Running)

vnstat running in Terminal 2

• Use appimageupdatetool OR Zsync (Terminal: 3)

• Stop vnstat & vnstatd (Press Ctrl + C)

rx shows total bandwidth

• Notice the Size of Original AppImage & Total Bandwidth used

QBittorrent using full bandwidth regardless of "delta" updates

• Re Run the entire test, but this time use soar update

• Notice, it only uses little to no bandwidth to compare the version to our remote repositories

• Notice, if update is found, both zsync-appimages & soar update use equal bandwidth. There's no actual Delta Update for zsync-appimages