zkevm-sequence-sender

Stateless autonomous binary to sequence L2 batches and send them to L1.

Architecture

• Sequence Sender: Gets batches from the datastream, detects when they have been closed, and aggregates as many of them as possible. Then decides the time to send those batches to L1 to get its state to transition to virtualized.

• JSON file: Persistence of transactions sent to L1. It is used as a cache for transaction management.

• Datastream client: Sequence Sender uses the stream client implemented in the data streamer library to connect to a datastream server.

• Datastream server: The data source is a datastream server, so the SequenceSender connects to the stream server to get information about L2 transactions, blocks, and batches.

• EthTxManager: Library used for sending and monitoring L1 transactions.

File

An example of the content of the JSON persistence file.

{
  "0x83014454cfd2989e8a82f31fce6f2eff19a3d44886cb36b365ee4d1cd6b159f3": {
    "nonce": 116,
    "status": "finalized",
    "sentL1Timestamp": "2024-02-09T11:09:00.04870821+01:00",
    "statusTimestamp": "2024-02-09T11:15:29.623881059+01:00",
    "fromBatch": 483,
    "toBatch": 483,
    "minedAtBlock": 5251050,
    "onMonitor": true,
    "to": "0x31a6ae85297dd0eebd66d7556941c33bd41d565c",
    "stateHistory": [
      "2024-02-09T11:09:00.048+01:00, *new, created",
      "2024-02-09T11:09:14.624+01:00, created, sent",
      "2024-02-09T11:11:14.629+01:00, sent, mined",
      "2024-02-09T11:13:14.625+01:00, mined, consolidated",
      "2024-02-09T11:15:29.623+01:00, consolidated, finalized"
    ],
    "txs": {
      "0x3876149295d876b09e92900d3fba2986d89c0572f8f7d345fa2ce8f058267282": {
        "gasPrice": 4426444863
      }
    }
  }  
}

Config

To the existing configuration in the SequenceSender section from the Node, the following new configuration parameters have been added:

The running mode of the sequence sender:

[SequenceSender]
Mode="validium" # or "rollup"

Maximum number of transactions pending completion. Once this number is reached, no new transactions will be sent until one completes (that reaches the consolidated state):

[SequenceSender]
MaxPendingTx=1

Wait time for a finalized transaction to be purged from the persistence file:

[SequenceSender]
WaitPeriodPurgeTxFile=48h

Reminder: Important to set the stream client config to point to the data stream server:

[SequenceSender]
  ...
	[SequenceSender.StreamClient]
		Server = "127.0.0.1:6900"

You can see a complete configuration file example here

Running SequenceSender

Build

Build the sequence sender executable file

make build

The binary file (zkevm-seqsender) will be left at path ./dist

Run

The execution command follows the format of the Node components. Example:

dist/zkevm-seqsender run --cfg ./test/config/local.node.config.toml --components sequence-sender

Another example setting a network customization file:

dist/zkevm-seqsender run --network custom --custom-network-file ./test/config/mynet.genesis.config.json --cfg ./test/config/mynet.config.toml --components sequence-sender