Multiple aggregators on a Mithril Network PoC

[jpraynaud]

Why

We want to allow multiple aggregators to run on the same Mithril network. Before going through a fully decentralized implementation, we want to implement prototype implementation of the Centralized signer registration and broadcast architecture.

What

• Implement the “Centralized registration and broadcast” architecture proposal for the signer registration.
• A master aggregator is responsible for receiving the signer registrations and broadcasting them to the slave aggregators.
• The master and slave aggregators are able to produce their own independent certificate chains (the certificate chain synchronization will be implemented in a future issue).

How

• The Mithril aggregator can run either in the master or the slave role in a Mithril network depending on configuration parameters.
• The slave aggregators are registered to the master aggregator.
• When a signer registers on the master aggregator, the slave aggregators are notified by a callback mechanism (with retries in case of unavailability).
• The slave aggregators are able to produce their own independent certificate chain and artifacts for the Mithril data types (in devnet and testnets only).
• The Mithril clients can interact seamlessly with any of the aggregators to download and verify Cardano database, transactions or stake distribution snapshots.