Nimbus falling back to doppelgänger unexpectedly about nimbus-eth2

[cheatfate]

Sorry, but this happens not unexpectedly, VC thinks that corresponding Beacon Node did not respond in time timeout=11s977ms979us74ns. So it considers that Beacon Node goes offline.

{"log":"WRN 2024-01-24 11:02:59.024+00:00 Unable to publish sync committee messages and contributions in time slot=8272512 timeout=11s977ms979us74ns service=sync_committee_service\n","stream":"stdout","time":"2024-01-24T11:02:59.024589419Z"}

In such case it reactivates doppelganger detection.

[stefa2k]

Thank you for taking the time looking into this issue! I discussed this with @tersec on Discord and we weren't sure what caused it. The Nimbus VC got 3 healthy beacon nodes, just the 4th one coming back to life, that's it. We (RockLogic) do this a lot, maintainance requires taking fullnodes connected to Nimbus VCs offline, updating, etc. and getting them online again. We never experienced this behaviour on the Nimbus VC before.

Discord messages: https://discord.com/channels/613988663034118151/613988663034118153/1199672828258168892

/E: Sorry, it was @arnetheduck whom I had the discussion, not tersec 🙏