historical plots of money supply, ceremony population size

[brenzi]

In the currency sidebar we could show historical plots with

• money supply vs time
• number of ceremony participants vs time
• number of tx/day
• tx volume /day

As this gh-pages homepage is stateless and the blockchain doesn't archive the history for easy queries, we would need to populate an external db with statistics

1. polkascan does exactly this: maintain a node and put all state updates in a queryable db
   • we would depend on polkascan to support (and maintain) our chain(s)
   • probably impractical for Testnet Cantillon and Mainnet where we'll have to do custom queries on enclave state to get money supply and ceremony statistics
2. develop and run our own archiver node, populating a db, (maybe forking from polkascan).
   • needs external service
   • possibly use grafana to render plots and serve entire dashboards
3. just scan recent history by RPC with at_block.
   • will be slow

[brenzi]

could we extend substrate's prometheus interface for these statistics?

[brenzi]

we may consider offchain indexing with custom RPC api to fetch history data