EPF Update 14

Summary

1. review Vid's pr #43 and #45
2. Create a draft pr on database user operation mempool -> https://github.com/Vid201/aa-bundler/pull/49
3. Join the second aa-bundler monthly meeting

MDBX

I used to have lots of experiences on LMDB which got a very similar api with MDBX. I googled about it and found MDBX is used to be a fork of LMDB and later development grows it into another powerful database engine.

Currently, there are serveral rust binding MDBX api available.

1. https://github.com/vorot93/libmdbx-rs
2. https://github.com/rmw-lib/mdbx
3. https://gitflic.ru/project/erthink/libmdbx
4. https://github.com/paradigmxyz/reth/tree/main/crates/storage/libmdbx-rs

Currently, after some investigations, I decided to use reth libmdbx-rs version because that would help us to integrate reth in the future.

I created a draft pr on it but tests are failing. I need to address this next week.

Notes from aa-bundler monthly notes(Copy from John's Email)

The core group has met twice to work on the specification.

1. Libp2p has been chosen as the communication protocol for the canonical mempool
2. Will use SSZ encoding and libp2p-noise encryption
3. Next is specifying the ENR structure
4. See the draft here: https://github.com/eth-infinitism/bundler-spec/blob/main/p2p-specs/p2p-interface.md

The EIP is undergoing an audit and nothing is known to impact the bundler so far.

There are no new bundler clients since the last meeting.