BlockUntilSyncedToCurrentChain: txindex is catching up on block notifications

Question

The message "BlockUntilSyncedToCurrentChain: txindex is catching up on block notifications" is appearing regularly in my debug.log. When these messages appear, I can be sure that lnd will not be able to complete syncing to the chain and thus unable to fully start.

This message occurs after the "txindex thread exit" message, and can be triggered with a "bitcoin-cli getrawtransaction xxx" call. I don't know how to resolve this, or even to determine what state the txindex is in. Restarting bitcoind does not help.

I am running Bitcoin Core version v0.18.0 (release build).

Answer 1

One way to solve this seems to be to disable and then reenable txindex. In other words, stop bitcoind, set txindex=0 in bitcoin.conf, start bitcoind, wait until fully started, stop bitcoind, set txindex=1, start bitcoind, wait until message "txindex is enabled at height xxx".

Unsure why this is necessary though.

Answer 2

For me it turned out that I had mempool.space running on my machine before bitcoind was done syncing the blockchain. I assume that mempool sends RPC calls to bitcoind in regular intervals, which then somehow causes this message to appear in the debug.log and often it seems that this message stops the blockchain syncing process and you have to restart bitcoind.

Simply shutting down mempool.space allowed bitcoind to then download the rest of the blockchain without any hickups, for me.