IF: Savanna Finality Network Health Observability

[bhazzard]

It would be helpful to have a reporting mechanism to monitor Savanna Finality Network Health. The primary goal of such a mechanism should be to ensure a healthy level of participation in the finality voting process by all top 21 Block Producers (BPs), who will serve as finalizers. This will enable the identification and addressing of any non-participatory finalizers, which is critical to ensure that finality can always advance on networks that adopt Savanna consensus.

The solution must:

• Extract quorum_certificate (QC) bitsets which indicate finalizer voting activity
• Correlate finalizer voting activity with finalizers based on the active finalizer policy
• Provide an HTTP endpoint for flexibility in how the data is consumed
• Provide Prometheus metrics for ease of integration with reporting tools
• Log finalizer voting information to nodeos
• Make it simple for block explorers to render finalizer voting information for every block containing a QC

The details of how voting activity will be correlated to finalizers and how the data will be represented in HTTP, prometheus, and nodeos logs are left for further discussion at a later time.