turn mplex off by default

[marten-seemann]

Checklist

• My issue is specific & actionable.
• I am not suggesting a protocol enhancement.
• I have searched on the issue tracker for my issue.

Description

libp2p has deprecated mplex for a long time. The implementation is not being maintained any more, and we're planning to drop it from our transport integration test suite due to its flakiness (read: bugs that we don't feel like debugging).

js-libp2p has had yamux support for a while now, as does rust-libp2p. Would it be a good time to say goodbye to our beloved mplex?

Done criteria

• mplex is not enabled by default
• Changelog specifies that mplex will be deprecated in the next Kubo release, how to reenable it, and points them that we'd like their feedback if they still require mplex. We should point to fully remove mplex #10069
• (nice to have) Log a warning if someone has mplex enabled.

[Jorropo]

👍 js-ipfs never got the yamux update, you have to add it in manually.

Given js-ipfs isn't maintained anymore we should remove thoses integration tests, ideally have new ones with helia. I did not had the courage to touch some JS when I tried in #9641.

[marten-seemann]

@ipfs/kubo-maintainers Is this in scope for the next release? Any reason to not do this rather sooner than later?

[BigLep]

Thanks for surfacing. We haven't set the scope for the next release. We will do so next week. I've put this down for consideration.

[BigLep]

@marten-seemann : this won't make it in for 0.22 since we need to clean up the interoperability story as well: #10013

I have this slotted for the next release (0.23) instead.

[aschmahmann]

note: updated the title to note that this about removing mplex support given that mplex has been the non-recommended transport for quite a while now.

[aschmahmann]

@achingbrain does js-ipfs support yamux or just helia? Trying to understand the scope of things that will break (and their update stories) if/when mplex support is removed.

[Jorropo]

I was not happy with the last PR, I wanted to turn it off by default for a release and remove it next release.

This would give a 1 month gap for people to add yamux back to their js-ipfs instance or migrate to helia.

[BigLep]

I'm reopening this issue. This issue is done when we have code in place to disable mplex by default. This is happening in #10095 . Fully removing mplex is tracked in #10069

[BigLep]

@Jorropo @hacdias : I put some other comments in the done criteria. Feel free to adjust.

@Jorropo : given you're focused on the Bitswap test work, would this be useful to have @hacdias to fully finish off?

[Jorropo]

Mplex has been turned off by default in #10070.
#10095 exists to update go-libp2p and precisely handle the fact that libp2p don't have mplex support anymore while we do.

I think this should be closed.

I have already told @hacdias what were the mplex items and he already implemented them in #10095, #10095's remainings things are:

• deal with the removal of quic draft 29 support (because all of our hardcoded maddrs are string we can't rely on the compiler to tell us everywhere they show up and have to manually handle them with grep and running tests until they fail)
  This maybe has been completed
• Reviews

[BigLep]

Thanks @Jorropo, you're right - my bad. Agreed this can stay close since we have met the done criteria and we're making sure new work (i.e., go-libp2p upgrade) continues to meet this criteria.