Rapid Relayer

Rapid Relayer is a fast, scalable, stateful IBC Relayer optimized for interwoven rollups.

Rapid Relayer does not use the tx_search query of Hermes to handle packets from several blocks at once. Initia Labs has developed this IBC Relayer to replace Hermes, only using the necessary functions for packet handling.

Problems We Faced

• Minitia L2s generate blocks extremely quick at 500ms per block.
• Due to the interwoven nature of Initia, often many IBC packets are generated within blocks. Hermes can handle batches of packets but on a single block basis.
• Hermes handles these IBC packets sequentially leading to unprocessed packets accumulating very quickly when having fast blocktimes.
• If Hermes stops, unprocessed packets will continue to pile up.
• When Hermes misses a packet, it finds them using tx_search query on every sequence, this can take minutes for just a few hundred packets.
• We need something more rapid.

How We Fix This

• We removed the tx_search query, and handle packets in parallel across several blocks at once.
• Keep track of synced_height and latest_height.
• Multi-threaded workers: packet handler and event feeder. The event feeder feeds the packet from new blocks to a cache and the packet handler fetches packets from it. This way, even if the packet handler stops, the event feeder will continue to operate.
• We remove the slow call of tx_search.

Installation

1. Clone the repository

git clone https://github.com/initia-labs/rapid-relayer.git

2. Install dependencies

npm install

Usage

1. Set config

{
  "$schema": "./config.schema.json",
  "port": 7010,
  "metricPort": 70001,
  "logLevel": "info",
  "chains": [
    {
      "bech32Prefix": "init",
      "chainId": "chain-1",
      "gasPrice": "0.15gas",
      "restUri": "https://rest.chain-1.com",
      "rpcUri": "https://rpc.chain-1.com",
      "wallets": [
        {
          "key": {
            "type": "raw",
            "privateKey": "123..."
          },
          "maxHandlePacket": 10,
          "startHeight": 0 // if empty start from the latest height
        },
        {
          "key": {
            "type": "mnemonic",
            "privateKey": "repair family apology column ..."
          },
          "maxHandlePacket": 10,
          "packetFilter": {
            "connections": [{ "connectionId": "conneciton-1" }]
          }
        }
      ],
      "feeFilter": {
        "recvFee": [{ "denom": "gas", "amount": 100 }],
        "timeoutFee": [{ "denom": "gas", "amount": 200 }],
        "ackFee": [{ "denom": "gas", "amount": 300 }]
      }
    },
    {
      "bech32Prefix": "init",
      "chainId": "chain-2",
      "gasPrice": "0umin",
      "restUri": "https://rest.chain-2.com",
      "rpcUri": "https://rpc.chain-2.com",
      "wallets": [
        {
          "key": {
            "type": "raw",
            "privateKey": "123..."
          },
          "maxHandlePacket": 10
        }
      ]
    }
  ]
}

2. Run relayer

npm start

Install via docker

docker build -t  your-tag .

mount a volume called '/config' which contains your config.json and a /syncInfo volume which will contain the state

docker run -it -v/tmp/rr/config:/config -v/tmp/rr/syncInfo:/syncInfo -d  rapid-relayer:latest

this should start the relayer in a docker container using your config, and placing the state in a separate volume