Voted to adopt proposal 133436.
This proposal replaces 3 nodes identified as dead or degraded in subnet lhg73 and does so without any negative impacts on Nakamoto coefficients or target topology.
The decentralization tool shows the current and to-be-added nodes in this subnet like so:
The nodes to be replaced are:
- ddbl6 - shown on the IC Dashboard as “Status: Offline”. In the Node Provider Rewards tool it appears to be working reasonably well, with a block failure rate of about 2% on the last day shown and a lower rate for several days prior.
- ffsue - shown on the IC Dashboard as “Status: Degraded / Status Details: IC_Replica_Behind”. It appears to be functioning poorly with a block failure rate ranging from 5% to 16% over the last 5 days.
- rs26k - shown on the IC Dashboard as “Status: Offline”. This was one of the nodes added a few days ago in proposal 133404. It appears only to have been assigned for one day (or less) with a block failure rate just under 4%.
Additionally, node ixo23 appears in the decentralization tool as “DOWN” and in the dashboard as “Status: Offline” but is not mentioned in this proposal. It appears to have been functioning well until yesterday (17 Oct), when it experienced a block failure rate of 38%.
I’ve voted to adopt this proposal as it replaces at least 2 poorly functioning nodes while maintaining decentralisation targets, and there is clearly an issue with this subnet that needs ongoing and prompt maintenance.
Questions: What rate of block failure is considered sufficiently bad to warrant replacing a node? From my understanding so far, I would probably have replaced ffsue, rs26k and ixo23 and left ddbl6 alone. Am I missing anything? What tools is Dfinity using to make this decision and which are the key metrics? In the event that there are only 9 functioning nodes in a 13-node subnet, does consensus now only need 7 nodes to agree instead of 9?