Re-executing state locally requires for us to listen to all new transactions (ingestion engine handles that) and re-execute all the transactions locally. In order to re-execute a transaction we need to have a state upon which the transaction is applied and we need to have a EVM which the transaction uses to be executed.
We are reusing the flow-go EVM Emulator for re-execution of the transaction, we just need to make sure we can provide the state. Emulator uses a atree.Ledger to fetch register values. We can plug-in the remote register API to fetch the registers upon a get function is called. This will simulate registers being present locally and will avoid the complexity of actually keeping the state locally.
The biggest concern with this approach is scalability. Most importantly will the register API requests be fast enough during the re-execution, so that the re-execution won't be delayed behind the on-chain state. If the latency of those requests is too high this approach won't work and we will have to move toward local register index #322
We should do stress-testing to figure out the scalability possibilities with this approach, with a local AN and EVM GW setup (so the latency of the network is minimized).
Re-executing state locally requires for us to listen to all new transactions (ingestion engine handles that) and re-execute all the transactions locally. In order to re-execute a transaction we need to have a state upon which the transaction is applied and we need to have a EVM which the transaction uses to be executed.
We are reusing the flow-go EVM Emulator for re-execution of the transaction, we just need to make sure we can provide the state. Emulator uses a
atree.Ledgerto fetch register values. We can plug-in the remote register API to fetch the registers upon a get function is called. This will simulate registers being present locally and will avoid the complexity of actually keeping the state locally.The biggest concern with this approach is scalability. Most importantly will the register API requests be fast enough during the re-execution, so that the re-execution won't be delayed behind the on-chain state. If the latency of those requests is too high this approach won't work and we will have to move toward local register index #322
We should do stress-testing to figure out the scalability possibilities with this approach, with a local AN and EVM GW setup (so the latency of the network is minimized).