[Announcement] Unconfirmed Wallet State Issues Incoming

[molnard]

1 hour ago the backend was restarted to update Bitcoin Core however Core failed to deserialize its mempool, so it started with a clean state. We wrote a script that tries to feed the backend with as many mempool transactions as possible from random Bitcoin nodes, which should save most of the trouble, but in some edge cases, wallet state inconsistency and fee estimation issues regarding unconfirmed transactions will still be experienced during the next few hours and possibly the next few days.

[ghost]

Can we also explicitly query nodes with large mempool sizes, like block explorers?

Default mempool size is 300 MB, but the total unconfirmed transaction size of mempool.space is 700 MB.

[molnard]

I am running a script on 2 PCs to feedback the mempool externally. At this moment:

$ bitcoin-cli getmempoolinfo
{
  "loaded": true,
  "size": 31864,
  "bytes": 32440688,
  "usage": 125892544,
  "total_fee": 7.88149212,
  "maxmempool": 300000000,
  "mempoolminfee": 0.00001000,
  "minrelaytxfee": 0.00001000,
  "unbroadcastcount": 510
}

[ghost]

fwiw, my node has a large enough mempool to not have dropped any transactions recently. Let me know if I can help to recover.

$ sudo bitcoin-cli getmempoolinfo
{
  "loaded": true,
  "size": 123341,
  "bytes": 199832172,
  "usage": 725320208,
  "maxmempool": 3000000000,
  "mempoolminfee": 0.00001000,
  "minrelaytxfee": 0.00001000
}

[ghost]

Maybe a solution is to increase the mempool size of the coordinator?

Previous considerations for keeping the default, is to stay in sync with other default nodes. But maybe the issue gets resolved if our mempool doesn't drop transactions at all.

---

But actually a question, is this issue on the backend mempool, or the client mempool?

[nopara73]

More in depth look at the issue: bitcoinknots/bitcoin#30

[molnard]

I cannot feed more tx with the backend it rejects all the tss because it already has it.
Current status:

$ bitcoin-cli getmempoolinfo
{
  "loaded": true,
  "size": 67238,
  "bytes": 77103255,
  "usage": 285585744,
  "total_fee": 8.36862484,
  "maxmempool": 300000000,
  "mempoolminfee": 0.00005620,
  "minrelaytxfee": 0.00001000,
  "unbroadcastcount": 29771
}

[ghost]

I still have more in my mempool.

sudo bitcoin-cli getmempoolinfo
{
  "loaded": true,
  "size": 111421,
  "bytes": 186989894,
  "usage": 670711712,
  "maxmempool": 3000000000,
  "mempoolminfee": 0.00001000,
  "minrelaytxfee": 0.00001000
}

[molnard]

Added a branch which we are using to feed the backend. It is dirty, no comments but working https://github.com/molnard/WalletWasabi/tree/mempoolfeeder

Just start Fluent.Desktop and observe the console. Don't need to do anything. @MaxHillebrand this is not using the local node but instead random nodes.

[ghost]

I run my nodes only on headless servers, so it seems I cannot use what you propose...?

[molnard]

It depends on your programming skills 😄

You can run it and see what happens if you are in experimental mood.