[ANSWERED] Transmission not honoring file priority

[rev]

As you can see in the picture below, looks like low priority = high priority.



I'm using Transmission 2.33 on Mac OS X 10.7.1

[blacke4dawn]

You misunderstand priority. Priority only influences the pieces your client actively asks for, however the other peers can still send you other pieces than the ones you ask for, and your client won't refuse any piece sent to it (unless the checksum fails). Most client prioritize sending the pieces with the lowest availability since that will increase the chances of others getting a full copy and ensuring a "healthy" cloud. Also, some of the peers you connect to may not have any "new" pieces belonging to a file you marked as high prio but may have for those you marked low, so of course they will send what they can.

Taking all that into account it's perfectly possible to end up downloading low prio files before high prio ones.

[livings124]

lol @ http://forum.utorrent.com/viewtopic.php?id=105634

[rev]

@ livings124: Yeah I lol'd too. I found it so weird but I couldn't help myself to post it on both forums to see what would be the outcome

@blacke4dawn: Oh. I always thought the client would only ask for the high priority files first and that I could only receive what I've asked for.
So it seems my client is asking for file 1 and some peers are answering "ok I'll send you file 1 but hey take file 3 too!". Would that be the case?
I still find this weird though, if I didn't ask for file 3 then I shouldn't receive pieces of file 3. But maybe that's how BitTorrent works.

[blacke4dawn]

Essentially yes.

It's not really weird if you consider two points:
1) Other peers can only send you pieces (files) that They have and that you don't already have.
2) They try to keep the availability of all pieces as even as possible within the swarm, so as to make it easier for new ones to get the full download.


Manually set priority is only one part of what determines what pieces to ask for.

[rev]

Right, it does make sense now. Thank you for the explanation blacke4dawn!