High level summary
During the past two weeks we made some important progress in the Genesis design.
It seems the BlockFetch logic need not be modified for Genesis, although this
needs to be confirmed. We started a DoS mitigation handbook and updated our
conceptual component diagram to guide the Genesis design. We engaged with the
IOG researchers to work on the Limit on Patience attack vector, work in this
area is still ongoing. We sketched a design to decouple the CPU load of the node
from its responsiveness to the socket. Finally, we discussed with Networking our
approach to lower the performance impact of the BlockFetch decision logic, and
got green light from them.
We migrated the consensus code to a new
repository, splitting
it from the ouroboros-network repository, and released version 0.6 of
Consensus.
We also merged the mempool fairness improvement to main branch.
Another significant enhancement to our documentation was the addition of an explanation of the hardfork combinator forecast horizon.
See the sections below for more details.
Genesis
We reviewed the BlockFetch design documentation, and added some source-code
comments that emphasize certain properties of the decisions the BlockFetch
logic makes that are helping us confirm that Genesis does not require any
changes to BlockFetch. We are waiting on input from our former system
architect to verify this.
We migrated and updated the conceptual component diagram in the ouroboros-consensus
repository which helps us situate the Genesis design and argument.
We engaged with the IOG researchers about the Genesis design. We sketched out a way to address the concern that the Limit on Patiente (LoP) attack vector duty cycle is indeed low, but it's still non-trivial to ultimately conclude it's sufficiently low.
We also sketched a design to decouple the CPU load of the node from its responsiveness to the socket, since the LoP is a relatively tight timeout, and node performance bugs inducing seconds-worth of latency are unfortunately familiar phenomena.
Fostering collaboration
We added an explanation of a question that we had to explain many times about the exact behavior of the hardfork combinator forecast horizon.