Setting up an ordering node

In this topic, we'll describe the process for bootstrapping an ordering node. If you want more information about the different ordering service implementations and their relative strengths and weaknesses, check out our conceptual documentation about ordering.

Broadly, this topic will involve a few interrelated steps:

  1. Creating the organization your ordering node belongs to (if you have not already done so)
  2. Configuring your node (using orderer.yaml)
  3. Creating the genesis block for the orderer system channel
  4. Bootstrapping the orderer

Note: this topic assumes you have already pulled the Hyperledger Fabric orderer images from docker hub.

Create an organization definition

Like peers, all orderers must belong to an organization that must be created before the orderer itself is created. This organization has a definition encapsulated by a Membership Service Provider (MSP) that is created by a Certificate Authority (CA) dedicated to creating the certificates and MSP for the organization.

For information about creating a CA and using it to create users and an MSP, check out the Fabric CA user's guide.

Configure your node

The configuration of the orderer is handled through a yaml file called orderer.yaml. The FABRIC_CFG_PATH environment variable is used to point to an orderer.yaml file you've configured, which will extract a series of files and certificates on your file system.

To look at a sample orderer.yaml, check out the fabric-samples github repo, which should be read and studied closely before proceeding. Note in particular a few values:

  • LocalMSPID --- this is the name of the MSP, generated by your CA, of your orderer organization. This is where your orderer organization admins will be listed.
  • LocalMSPDir --- the place in your file system where the local MSP is located.
  • # TLS enabled, Enabled: false. This is where you specify whether you want to enable TLS. If you set this value to true, you will have to specify the locations of the relevant TLS certificates. Note that this is mandatory for Raft nodes.
  • BootstrapFile --- this is the name of the genesis block you will generate for this ordering service.
  • BootstrapMethod --- the method by which the bootstrap block is given. For now, this can only be file, in which the file in the BootstrapFile is specified.

If you are deploying this node as part of a cluster (for example, as part of a cluster of Raft nodes), make note of the Cluster and Consensus sections.

If you plan to deploy a Kafka based ordering service, you will need to complete the Kafka section.

Generate the genesis block of the orderer

The first block of a newly created channel is known as a "genesis block". If this genesis block is being created as part of the creation of a new network (in other words, if the orderer being created will not be joined to an existing cluster of orderers), then this genesis block will be the first block of the "orderer system channel" (also known as the "ordering system channel"), a special channel managed by the orderer admins which includes a list of the organizations permitted to create channels. The genesis block of the orderer system channel is special: it must be created and included in the configuration of the node before the node can be started.

To learn how to create a genesis block using the configtxgen tool, check out Channel Configuration (configtx).

Bootstrap the ordering node

Once you have built the images, created the MSP, configured your orderer.yaml, and created the genesis block, you're ready to start your orderer using a command that will look similar to:

docker-compose -f docker-compose-cli.yaml up -d --no-deps orderer.example.com

With the address of your orderer replacing orderer.example.com.