The dropper periodically disconnects random peers to create churn.
This was blind to peer quality. Add inclusion-based peer protection
using two categories:
1. Total inclusions: protects peers with the highest cumulative
count of delivered txs that were included on chain
2. Recent inclusions (EMA): protects peers with the best recent
inclusion rate, giving newly productive peers faster protection
Each category independently protects the top 10% of inbound and
top 10% of dialed peers. The union of both sets is protected. Only
peers with positive scores qualify.
The dropper defines its own PeerInclusionStats struct and callback
type (getPeerInclusionStatsFunc) so any stats provider (e.g. a
transaction tracker) can plug in without a package dependency. The
callback is nil by default (protection disabled until wired).
The protectionCategories slice is designed for easy extension —
adding a new category requires only appending a struct with a name,
scoring function, and protection fraction.
As of now, Geth disconnects peers only on protocol error or timeout,
meaning once connection slots are filled, the peerset is largely fixed.
As mentioned in https://github.com/ethereum/go-ethereum/issues/31321,
Geth should occasionally disconnect peers to ensure some churn.
What/when to disconnect could depend on:
- the state of geth (e.g. sync or not)
- current number of peers
- peer level metrics
This PR adds a very slow churn using a random drop.
---------
Signed-off-by: Csaba Kiraly <csaba.kiraly@gmail.com>
Co-authored-by: Felix Lange <fjl@twurst.com>
