Logs: `feerate estimate for min_acceptable hit floor 253`. Infinite loop?

[callebtc]

Issue and Steps to Reproduce

I used Polar 1.4.1 to install CLN v23.02.2 in my local regtest and opened one outgoing channel to an LND node (v0.15.0).

The node operates normally but when I watch the logs, I see the following lines repeat every 2 seconds infinitely:

2023-05-03T07:16:42.320Z DEBUG   lightningd: ... feerate estimate for opening hit floor 253
2023-05-03T07:16:42.320Z DEBUG   lightningd: ... feerate estimate for mutual_close hit floor 253
2023-05-03T07:16:42.320Z DEBUG   lightningd: ... feerate estimate for unilateral_close hit floor 253
2023-05-03T07:16:42.320Z DEBUG   lightningd: ... feerate estimate for delayed_to_us hit floor 253
2023-05-03T07:16:42.320Z DEBUG   lightningd: ... feerate estimate for htlc_resolution hit floor 253
2023-05-03T07:16:42.320Z DEBUG   lightningd: ... feerate estimate for penalty hit floor 253
2023-05-03T07:16:42.320Z DEBUG   lightningd: ... polled feerate estimate for min_acceptable (125) smoothed to 248 (alpha=0.04)
2023-05-03T07:16:42.320Z DEBUG   lightningd: ... feerate estimate for min_acceptable hit floor 253

I'm not sure if this is supposed to be or not but it looks like an infinite loop to me. Please close and ignore this Issue if this is the intended behavior.

getinfo output

lightning-cli getinfo
{
   "id": "02fcbcc75f7b8908cd54f42ec09c9dfd13548b5782a76067b4e24eb0fb54ac6f61",
   "alias": "erin",
   "color": "02fcbc",
   "num_peers": 3,
   "num_pending_channels": 0,
   "num_active_channels": 1,
   "num_inactive_channels": 0,
   "address": [],
   "binding": [
      {
         "type": "ipv4",
         "address": "172.18.0.7",
         "port": 19846
      },
      {
         "type": "ipv4",
         "address": "0.0.0.0",
         "port": 9735
      }
   ],
   "version": "v23.02.2",
   "blockheight": 201,
   "network": "regtest",
   "msatoshi_fees_collected": 0,
   "fees_collected_msat": "0msat",
   "lightning-dir": "/home/clightning/.lightning/regtest",
   "our_features": {
      "init": "08a000080269a2",
      "node": "88a000080269a2",
      "channel": "",
      "invoice": "02000000024100"
   }
}

[vincenzopalazzo]

Does this look like an out-of-range fee? Is CLN trying to check if there is a new fee rate that meets the HTLC requirements?

[rustyrussell]

It's spammy, but expected on regtest. They're presumably using the dev option to poll bitcoind every 2 seconds (vs default 60, great for testing!), so you're seeing a whole pile of these. I think I'll remove this msg since it's not very useful!