Connection unexpectedly failed: Unexpected exception while connecting to socket

Since yesterday (apparently at block height 774627), I’m getting the same error as in #170, but with the problem and solution therein definitely not applying to my setup.

I had been running NBXplorer for BTCPayServer for years now, and when this exception first appeared it was on version 2.2.20. So the first thing I tried was upgrading to 2.3.58, and subsequently upgrading bitcoind from 23.0 to 24.0.1. However, the exception persists and it’s unable keep a connection open to bitcoind apparently. The full log looks like this:

info: Configuration:  BTC: Full node version detected: 240001
info: Configuration:  BTC: Node banlist loaded
info: Configuration:  BTC: Loading chain from cache...
info: Configuration:  BTC: Height: 774835
info: Configuration:  BTC: Trying to connect via the P2P protocol to trusted node (127.0.0.1:8333)...
info: Explorer:       BTC: TCP Connection succeed, handshaking...
info: Explorer:       BTC: Handshaked
info: Configuration:  BTC: Loading chain from node
info: Explorer:       BTC: Loading chain...
info: Explorer:       BTC: Chain loaded
info: Explorer:       BTC: NBXplorer is correctly whitelisted by the node
info: Configuration:  BTC: Height: 774836
info: Configuration:  BTC: Saving chain to cache...
info: Configuration:  BTC: Chain cached
info: Explorer:       BTC: Handshaked node
info: Explorer:       BTC: Starting scan at block 774627
info: Events:         BTC: Node state changed: NotStarted => NBXplorerSynching
fail: Explorer:       BTC: Connection unexpectedly failed: Unexpected exception while connecting to socket
info: Events:         BTC: Node state changed: NBXplorerSynching => NotStarted
info: Configuration:  BTC: Testing RPC connection to http://127.0.0.1:8332/
fail: Explorer:       BTC: Unhandled error in IndexBlockLoop
fail: Explorer:       System.OperationCanceledException: The peer has been disconnected
         at NBXplorer.BlockDownloader.DownloadBlocks(BlockLocator fork, CancellationToken cancellationToken)+MoveNext() in /opt/nbxplorer/NBXplorer/BlockDownloader.cs:line 57
         at NBXplorer.BlockDownloader.DownloadBlocks(BlockLocator fork, CancellationToken cancellationToken)+System.Threading.Tasks.Sources.IValueTaskSource<System.Boolean>.GetResult()
         at NBXplorer.ExplorerBehavior.IndexBlockLoop(Node node, CancellationToken cancellationToken) in /opt/nbxplorer/NBXplorer/ExplorerBehavior.cs:line 319
         at NBXplorer.ExplorerBehavior.IndexBlockLoop(Node node, CancellationToken cancellationToken) in /opt/nbxplorer/NBXplorer/ExplorerBehavior.cs:line 319
info: Configuration:  BTC: RPC connection successful
info: Configuration:  BTC: Full node version detected: 240001
info: Configuration:  BTC: Loading chain from cache...

[raucao]

2.3.60 didn’t fix it for me. But migrating to Postgres worked.

Thanks. 🙏

[NicolasDorier]

Also you can try v2.3.60 that I just pushed, that may solve your issue on the old backend. But once again, I advise you to use a postgres backend.

To migrate, use env variables: (you can keep them after migrating without issue)

      NBXPLORER_POSTGRES: User ID=postgres;Host=postgres;Port=5432;Application Name=nbxplorer;MaxPoolSize=20;Database=nbxplorer
      NBXPLORER_AUTOMIGRATE: 1
      NBXPLORER_NOMIGRATEEVTS: 1

If you run btcpay with you get more feature using the new backend:

BTCPAY_EXPLORERPOSTGRES: User ID=postgres;Host=postgres;Port=5432;Application Name=btcpayserver;MaxPoolSize=80;Database=nbxplorer