Mission downloader which mirror?

[datiswous]

What mirror is used for the ingame mission downloader?

I wonder if it's using the best mirror.

[datiswous]

I find some of the missions so large that I no longer want to wait inside tdm till it's downloaded. Fortunately there's an alternative.

[freyk]

I dont know.

It would be nice for in the future, to create a tdm config file where you can add links to fm mission mirrors, like a linux app repo list.

Edited September 8 by freyk

[chakkman]

The downloads often vary in terms of speed, so, I assume that it uses different mirrors.

[taffernicus]

Today I tried downloading 3 different Fan missions. I fired up tcpdump with the intention of capturing all download traffics and opening the saved .pcap/pcapng file in wireshark. These are the results I got:

- Downloading hidden hands blood & metal for the first time :

- Getting sneak & shouffle FM from official TDM server( previously downloaded but I tried to download again) :

- Downloading Terrible Old man :

I can attest that the URL mirror choices can be different.

If we start from the first sequence of clicking the download mission menu and let TDM fetch the list of fan missions from the server, we will find an xml return result together with HTTP 200 OK status :

Nothing appealing from this xml wall of texts.  I had one question in mind: what caused the randomness of the URL mirror choices? For a moment, my eyes were drawn and laser focused to the "weight" attribute. Is it possible that the weight determines the randomness?

Not long afterwards, I skim-read TDM source files in the official TDM's svn repo (honestly I'm not used to reading large codebases) and I found this interesting piece of codes in file called MissionManager.cpp:

Could this code be a factor of randomness?

*I also skim read directory /missions and /http where some http code is located.

Warning : C++ isn't my strongest forte so take this with a grain of salt. Perhaps official TDM devs could weigh in into this discussion...

Edited September 9 by taffernicus
broken img embed fix

[stgatilov]

Just like for tdm_installer, the mirror for mission download is selected randomly.

There are also weights intended to distribute traffic across mirrors.
While you might be interested in using the fastest mirror only, controlled random distribution is used because some mirror owners were worried about too much traffic.