1. GRPC health check on Erigon and RPC Daemon, activated by --healthcheck command line option (thanks to external contributor “primalcs”). Documentation still needs to be written, but it follows this: https://github.com/grpc/grpc/blob/master/doc/health-checking.md
2. docker-compose.yml now includes option for RPC Daemon to connect to the transaction pool.
3. Support for eth/65 p2p protocol is removed, reducing number of internal sentries from 2 to 1, and consequently number of peers by default.
4. Transaction pool now supports debugging for specific sender addresses using --txpool.trace.senders option. It takes comma-separated list of addresses and prints detailed information about all transactions sent by specified addresses. It can be used for investigation of issues with the transaction pool.
5. Checks for potential database schema downgrades. Erigon 1 beta and Erigon 2 will soon diverge on their database layout and from now on users will not be able to use the same database with Erigon 1 beta and Erigon 2 interchangeably. Checks in the code are designed to protect from accidental DB upgrades or downgrades.
6. Transaction broadcasting. Previously, pending transactions were announced (by sending their hashes), but not broadcast. Now they are broadcast to a random subset of peers. For local transactions, the log output now shows how many peers they have been announced and broadcast to.
7. Fix of a bug in the transaction pool that caused local transactions not being announced or broadcast when their dependent transaction is promoted or replaced by higher fee.
8. Updates to pre-verified hashes for Ropsten and Mainnet, change of skip analysis optimisation parameter