Remove GetNodeData and NodeData messages from the wire protocol
|Authors||Marius van der Wijden (@MariusVanDerWijden), Felix Lange <firstname.lastname@example.org>, Gary Rong <email@example.com>|
Table of Contents
The Ethereum Wire Protocol defines request and response messages for exchanging data between clients. The
GetNodeData request retrieves a set of trie nodes or contract code from the state trie by hash. We propose to remove the
NodeData messages from the wire protocol.
NodeData were introduced in protocol version
eth/63 to allow for a sync mode called “fast sync”, which downloads the Ethereum state without executing all blocks. The sync algorithm works by requesting all state trie nodes and contract codes by their hash.
GetNodeData requests requires clients to store state as a mapping of hashes to trie nodes. Avoiding the need to store such a mapping in the database is the main motivation for removing this request type.
At this time, some client implementations cannot serve
GetNodeData requests because they do not store the state in a compatible way. The Ethereum Wire Protocol should accurately reflect the capabilities of clients, and should not contain messages which are impossible to implement in some clients.
Remove the following message types from the
[request_id: P, [hash_0: B_32, hash_1: B_32, ...]]
[request_id: P, [value_0: B, value_1: B, ...]]
A replacement for
GetNodeData is available in the snap protocol. Specifically, clients can use the GetByteCodes and GetTrieNodes messages instead of
GetNodeData. The snap protocol can be used to implement the “fast sync” algorithm, though it is recommended to use it for “snap sync”.
This EIP changes the
eth protocol and requires rolling out a new version,
eth/67. Supporting multiple versions of a wire protocol is possible. Rolling out a new version does not break older clients immediately, since they can keep using protocol version
This EIP does not change consensus rules of the EVM and does not require a hard fork.
Copyright and related rights waived via CC0.
Please cite this document as:
Marius van der Wijden (@MariusVanDerWijden), Felix Lange <firstname.lastname@example.org>, Gary Rong <email@example.com>, "EIP-4938: eth/67 - Removal of GetNodeData [DRAFT]," Ethereum Improvement Proposals, no. 4938, March 2022. [Online serial]. Available: https://eips.ethereum.org/EIPS/eip-4938.