[Project tracking] Cross shard bandwidth limits

[jancionear]

• Central doc: https://docs.google.com/document/d/1ypp-RahbfibGypPcfh7LdnLq2xSKGXd505-aovDPYcQ/edit#heading=h.6n0d8rflejy8

[walnut-the-cat]

Aug 30th report:

• lots of thinking and discussions. Making progress, it seems that we have a few potential designs to choose from, now we have to iron out all the details and choose which one to go with.
  • Design doc link

[walnut-the-cat]

Sept 2-6

• Created a central doc
• Considered a few different solutions to the problem, created quick docs for each one
• Decided to go with option C2

Sept 9-13

• Not too much progress due to focus on release engineering

[jancionear]

Sept 16-20

• Writing a NEP which describes the chosen design, WIP version
• Finalizing the design, started writing a simulator to test and validate the algorithm

Sept 23-27

• Implemented a bandwidth scheduler simulator. It simulates a blockchain that sends receipts between shards in different ways with missing chunks and blocks. Implemented a few different scenarios to test that the BandwidthScheduler maintains high bandwidth utilization and fairness. The initial design had some flaws, but I improved the algorithm and now it's able to achieve the desired behavior. zulip
• The algorithm has been verified on the simulator, it's now ready for implementation in nearcore