Start indexing consensus from recent height, just to have a current node registry snapshot

[csillag]

This is an old, closed issue, migrated here for historical reference. No action necessary.

We want to show the number of sapphire/emerald nodes.

We don't care about other consensus data right now. So let's just index recent consensus heights; the registry is always downloaded as a whole, not in the form of incremental diffs.

Doing this will cause indexing to halt because of >0 checks for balances. A not-so-hacky workaround would be to implement (and hardcode, for now) fast-sync mode in the consensus analyzer.

First precondition:

• analyzer: genesis: parse compute nodes for each runtime #458

Second precondition:

• no-dead-reckoning mode (=fast-sync mode) so we don't produce negative balances: consensus: fast-sync mode: Skip dead reckoning #457
  OR
• start using GenesisAtHeight() ( Ability to run analyzers in parallel #456 ) so that dead reckoning from that height on will not produce negative balances.

[csillag]

@mitjat says:

We won't be doing this hack. Frontend hardcoded a number of active nodes. Let's bring up consensus in a normal way.