Does iroh-gossip guarantee that messages sent by the same sender are received by everyone in the same order?

[b5]

I'm almost positive it doesn't, but either way, we need to document an answer on what the current behavior is

[link2xt]

Related deltachat issue: deltachat/deltachat-core-rust#5688
Delta Chat does not need guarantee, but reordering should not be introduced on the sender if possible, e.g. no spawning of tasks for each message sent etc. If packets are lost/reordered on IP level or gossip tree is rebuilt (i.e. there are routing changes), then reordering gossip messages is fine.

[divagant-martian]

There is no notion of order in gossip at all, and a perceived non-order is expected simply given the existence of lazy peers, which might be eager peers of our eager peers. This is a known not-guarantee and I doubt we should try to make it one even in the simple cases

[link2xt]

This happens even when I have only two peers. One node is sending data and there seems to be no reason the second node receives it in the other order.

[link2xt]

The issue can probably be closed on the iroh side, I made a python test and don't see any reordering when sending 200 messages in a row: deltachat/deltachat-core-rust#5696
So likely the problem is somewhere on the higher layer, e.g. Delta Chat UI or Node.js bot.

[dignifiedquire]

Thanks, closing, please let us know if you find an issue with iroh