Configure Sequencer Backend¶

The following page describes the basics of configuring Sequencer backends. For more advanced configuration, refer to the following sections:

High availability

Pruning

Optimization

Database Sequencer¶

The Database Sequencer is currently unsupported and should not be configured.

BFT Sequencer¶

Minimal BFT Sequencer backend configuration¶

To use the Byzantine Fault Tolerant (BFT) Sequencer, set the type parameter to BFT under sequencer:

sequencers {
  sequencer1 {
    sequencer.type = BFT
  }
}

Note that this configuration is for single-node networks; you cannot add peers. For multi-node networks, refer to the next section.

Configure initial peers (optional)¶

If the network contains more than one node, configure the server endpoint under initial-network. There, you can also configure peer endpoints, or do so using admin commands later. Pre-configuring the peer endpoints reduces the number of manual configuration steps, which saves time, reduces errors, and accelerates the deployment process.

server-endpoint {
  address = "0.0.0.0"
  port = 31030
  external-address = "127.0.0.1"
  external-port = 31030
  external-tls-config.enabled = false
}
peer-endpoints = [
  {
    address = "127.0.0.1"
    port = 31031
    tls-config.enabled = false
  }
]

The address and port pair under server-endpoint make up an endpoint where the BFT Sequencer’s gRPC server listens. If the port is not specified, the operating system chooses one for you. The external-address and external-port form an externally available endpoint that other peers can connect to. Usually, the external-address is the domain name of a reverse proxy that points to the listening endpoint. The external endpoint must be configured correctly for clients to successfully authenticate the server.

Transport Layer Security (TLS) is enabled by default for the external endpoint and peer endpoints. For simplicity, it is disabled in the config example. However, it is recommended to configure it in the standard way with:

tls under server-endpoint for the internal server endpoint

external-tls-config under server-endpoint for the external endpoint

tls-config under peer-endpoints for peer endpoints

For more details on the initial-network configuration, check the reference documentation.

Configure authentication (optional)¶

Authentication is enabled by default. It can be configured with endpoint-authentication under initial-network (at the same level as server-endpoint):

endpoint-authentication {
  auth-token = {}
}

For more details on authentication, visit the secure Synchronizer page.

Configure dedicated storage (optional)¶

To use dedicated storage, configure storage under config as for the top-level Sequencer storage configuration.

While the BFT Sequencer defaults to using the top-level Sequencer storage, configuring dedicated storage offers greater flexibility. It allows you to:

Support distinct data read and write patterns with different database backends and settings

Separate backups

Configure network-wide parameters¶

If you change the defaults, keep the following parameters in sync across the network:

epoch-length: a length of all epochs

max-requests-in-batch: a maximum number of requests in a batch, validated at runtime

max-batches-per-block-proposal: a maximum number of batches per block proposal, validated at runtime

All the above parameters reside under config and must be the same across all BFT Orderer nodes.

For details on the related concepts, check the BFT Orderer explanation page.

Configure other (local) parameters¶

There are other (local) configuration parameters under config that can be changed.

For details, check the reference documentation.

External Sequencer¶

To use an external Sequencer (for example, CometBFT), configure the underlying Sequencer type under config in the sequencer configuration:

sequencer {
    config {
        cometbft-node-host = "127.0.0.1"
        cometbft-node-port = 26627
    }
    type = CometBFT
}

Every external Sequencer requires a corresponding Sequencer Driver on the classpath.