bitcoind as a JDC (without making it into a proxy)

[plebhash]

During our IRL meeting in BTC Prague, we brainstormed a new SV2 configuration.

The context is that @Sjors wants to add a JDC functionality to bitcoind. On this use case, bitcoind is no longer focused Template Distribution Protocol, and it is effectively doing a JDC role.

A few potential implications:

• new messages to Job Declarator Protocol
• new functionality to Proxy implementations

The image below is a dirty braindump. @Sjors @GitGab19 we should refine the idea on the comments below here.

Note: PoolSucks is just a casual/funny name for a new message we came up during this brainstorming. Obviously we would need a more formal name in case this idea moves forward.

[Sjors]

Thanks for taking notes and drawing this diagram!

[GitGab19]

The tricky part I remember we discussed was related to pool-fallback mechanism.
There would be 2 triggers for that:

• A valid share is rejected by POOL with a SubmitSharesError message (I think we should discuss if this trigger makes sense at all, since there could be cases in which a share is stale for the pool, but not for the miner yet)
  • in this case the Proxy should alert the bitcoind-JDC about that, asking for a new job declaration with the secondary upstream
• A custom job is refused by JDS with a DeclareMiningJobError message, so in this case the bitcoind-JDC should trigger the fallback and tell the Proxy the new upstream where to send shares to

[GitGab19]

Besides of these details, it could be also useful to log the reasons why we started this brainstorming.
@Sjors could you provide some context about this?

[Fi3]

yep I wanted to leave a comment. But I realized that I don't know why we need it. So I will wait

[plebhash]

#85 (comment)

[Sjors]

There's some context here: bitcoin/bitcoin#29346 (comment)

Mainly I'd like the simplest setup to be Bitcoin Core + miner, without the need to also install configure SRI tools. But as we discussed it's quite tricky.

---

One simpler idea I'd like to try to implement is Stratum v2 solo mining with only Bitcoin Core.

[Fi3]

not sure what typical is. I only played with s9 control board and should handle it without issues

[Sjors]

That's good news. The other problem is that it creates a dependence on device manufactures to ship more stuff. And to update it.

So in the long run it's probably best to require as little functionality as possible on firmware.

[Fi3]

make sense. Btw if we go with this option, I think that would be nicer to have a PR accepted with the actual sv2 and then add the other pieces, otherwise I'm worried that will take ages.

[plebhash]

sorry @Fi3 just to clarify:

I think that would be nicer to have a PR accepted with the actual sv2

here you are referring to bitcoind doing TP role, correct?

[Fi3]

yep