Node Tracing / JSON RPC Requirements

Standard JSON RPC Requirements

• Archive node with JSON RPC interface should strictly follow input/output interface described in https://ethereum.github.io/execution-apis/api-documentation/
• WebSocket interface (optional/highly recommended to enable) is used to subscribe to new block heads. Otherwise, Blockscout will trigger new blocks fetching by periodical polling the JSON RPC eth_blockNumber method.
• Support for the following standard Ethereum JSON RPC methods (documented at https://ethereum.github.io/execution-apis/api-documentation/)
  • eth_blockNumber
  • eth_call
  • eth_getBalance
  • eth_getCode
  • eth_getBlockByHash
  • eth_getBlockByNumber
  • eth_getTransactionByHash
  • eth_getTransactionByBlockHashAndIndex
  • eth_getTransactionByBlockNumberAndIndex
  • eth_getTransactionReceipt
  • eth_getUncleByBlockHashAndIndex
  • eth_getLogs

Fetching Pending Transactions

Client	Method
Erigon Nethermind OpenEthereum	parity_pendingTransactions
Geth	txpool_content

Enable Tracing to Fetch Internal Transactions

Client	Method
Erigon Nethermind OpenEthereum	• trace_replayBlockTransactions (fetching of internal transactions) • trace_block (fetching of block rewards)
Geth	• debug_traceBlockByNumber • or debug_traceTransaction callTracer is used by default, starting from the Blockscout 5.1.0 release. To switch to a custom JS tracer, the Blockscout maintainer should set the export INDEXER_INTERNAL_TRANSACTIONS_TRACER_TYPE=js environment variable. Prior to the 5.1.0 release, js tracer was a default option.

JSON RPC Performance Benchmarks

Time measures for response time of crucial JSON RPC methods for indexing in Blockscout. Ways to improve speed.

1. eth_getBlockByNumber without transaction receipts for a block with 15 transactions: Desired response time is < 0.5s. For instance, in case of the Gnosis chain archive node, the response time for the block with ~20 transactions is ~0.4s.
2. eth_getTransactionReceipt for random transactions desired response time is < 0.5s. For the Gnosis chain archive node the response time is ~0.3 - 0.4s.
3. Batched eth_getTransactionReceipt for 15 transactions acceptable response time is Less than 1s. For the Gnosis chain archive node, it is ~0.6 - 0.7s

Rate Limit

The desired rate limit for RPC endpoint is 200 req/sec for the indexing phase and 100 req/sec for the indexed chain.

EVM Requirements & Clients

• All EVM chains must define these variables during configuration.
• BlockScout currently supports Erigon, Geth, Nethermind, Hyperledger Besu, and Anvil clients. Define the node variant using the ETHEREUM_JSONRPC_VARIANT environment variable. More information

L2 -> L1 JSON RPC Methods

• Find information on JSON RPC method use with different L2 types.