Blockchain Release: Resuming Block Production and Gossip

Hotspot Release

The core developers have tagged a new 2021.11.17.2 Hotspot firmware release which includes CRITICAL fixes to ensure that Hotspots continue to follow the chain after the 24 hr+ chain halt observed on November 15th.

This is a mandatory release for manufacturers to ensure that overall network gossip continues to work as expected.

Note: A full post-mortem will be shared with the community early next week.

Blockchain Halt Fixes

• Consensus group members were saving transaction proposals to disk more often than was needed. Proposal construction state has been changed to write to disk piecewise.
• There were numerous places where blocks were unnecessarily read from the disk, leading to disastrous performance with the unexpectedly large block. Most of these have been eliminated by better block metadata caching.
• General performance sweep of the entire transaction validation and absorb pathways.
• Rewrite two low level repositories, e2qc and vincenty, in Rust to improve performance
• Added block_size_limit chain variable which is defaulted to 50MB on miner but can be updated in the future with a chain variable transaction.

Please feel free to skim through the PRs mentioned below for more information.

PRs for resuming Hotspots sync

• blockchain-core#1108: Fix sync flag on add block events
• blockchain-core#1107: Ignore sync for recent blocks

PRs for resuming Blockchain

• miner#1213: Switch to block_info_v2

• miner#1210: Add a max block size when constructing blocks

• blockchain-core#1105: Fix snapshot info handling

• blockchain-core#1103: Update elections to not pull blocks

• blockchain-core#1098: Upgrade block info to include hbbft round and election info

• blockchain-core#1097: Remove two more unnecessary uses of head_block

• blockchain-core#1094: Add block_size_limit chain variable

• blockchain-core#1093: Add gossip_block_limit_mb application variable

• blockchain-core#1091: Do not send a stale state channel

• blockchain-core#1090: Various performance improvements from downstream

• relcast#48: Write keytree under txn in another spot

• relcast#47: Attempt to add other key types to relcast serialization tree

• erlang-hbbft#74: Attempt better serialization/deserialzation for rbc

• erlang-hbbft#73: Temporarily hardcode max rpc proposal size to 5mb

• erlang-hbbft#72: Attempt to use a keytree serialization for rbc to help performance

• vincenty#2: Switch vincenty backend to Rust

• e2qc#1: Switch e2qc backend to Rust

Plan

We have been beta testing 2021.11.17.2 since November 17, 2021 1:50 PM PT. Current ETA for GA is 4:30 PM PT, November 17, 2021.