Setting a subset of orderers for RAFT application channel

Question

I am trying to create an application channel using first-network from fabric-samples.

1. I am creating the deployment to run 4 ordering nodes running in RAFT cluster. The following is the profile section used for creating Orderer Genesis Block in the configtx.yaml file.

   SampleMultiNodeEtcdRaft
       <<: *ChannelDefaults
       Capabilities:
       <<: *ChannelCapabilities
       Orderer:
           <<: *OrdererDefaults
           OrdererType: etcdraft
           EtcdRaft:
               Consenters:
               - Host: orderer.example.com
                 Port: 7050
                 ClientTLSCert: crypto-config/ordererOrganizations/example.com/orderers/orderer.example.com/tls/server.crt
                 ServerTLSCert: crypto-config/ordererOrganizations/example.com/orderers/orderer.example.com/tls/server.crt
               - Host: orderer2.example.com
                 Port: 8050
                 ClientTLSCert: crypto-config/ordererOrganizations/example.com/orderers/orderer2.example.com/tls/server.crt
                 ServerTLSCert: crypto-config/ordererOrganizations/example.com/orderers/orderer2.example.com/tls/server.crt
               - Host: orderer3.example.com
                 Port: 9050
                 ClientTLSCert: crypto-config/ordererOrganizations/example.com/orderers/orderer3.example.com/tls/server.crt
                 ServerTLSCert: crypto-config/ordererOrganizations/example.com/orderers/orderer3.example.com/tls/server.crt
               - Host: orderer4.example.com
                 Port: 10050
                 ClientTLSCert: crypto-config/ordererOrganizations/example.com/orderers/orderer4.example.com/tls/server.crt
                 ServerTLSCert: crypto-config/ordererOrganizations/example.com/orderers/orderer4.example.com/tls/server.crt
           Addresses:
               - orderer.example.com:7050
               - orderer2.example.com:8050
               - orderer3.example.com:9050
               - orderer4.example.com:10050
           Organizations:
           - *OrdererOrg
           Capabilities:
               <<: *OrdererCapabilities
       Application:
           <<: *ApplicationDefaults
           Organizations:
           - <<: *OrdererOrg
       Consortiums:
           SampleConsortium:
               Organizations:
               - *Org1
               - *Org2
   

2. Now I want to create an application channel which will only have 3 ordering nodes (out of the given 4): orderer, orderer2, orderer3. So I set the profile section for application channel as follows (in the configtx.yaml file):

   TwoOrgsChannel:
       Consortium: SampleConsortium
       <<: *ChannelDefaults
       Capabilities:
           <<: *ChannelCapabilities
       Orderer:
           <<: *OrdererDefaults
           OrdererType: etcdraft
           EtcdRaft:
               Consenters:
               - Host: orderer.example.com
                 Port: 7050
                 ClientTLSCert: crypto-config/ordererOrganizations/example.com/orderers/orderer.example.com/tls/server.crt
                 ServerTLSCert: crypto-config/ordererOrganizations/example.com/orderers/orderer.example.com/tls/server.crt
               - Host: orderer2.example.com
                 Port: 8050
                 ClientTLSCert: crypto-config/ordererOrganizations/example.com/orderers/orderer2.example.com/tls/server.crt
                 ServerTLSCert: crypto-config/ordererOrganizations/example.com/orderers/orderer2.example.com/tls/server.crt
               - Host: orderer3.example.com
                 Port: 9050
                 ClientTLSCert: crypto-config/ordererOrganizations/example.com/orderers/orderer3.example.com/tls/server.crt
                 ServerTLSCert: crypto-config/ordererOrganizations/example.com/orderers/orderer3.example.com/tls/server.crt
           Addresses:
               - orderer.example.com:7050
               - orderer2.example.com:8050
               - orderer3.example.com:9050
           Organizations:
               - *OrdererOrg
           Capabilities:
               <<: *OrdererCapabilities
       Application:
           <<: *ApplicationDefaults
           Organizations:
               - *Org1
               - *Org2
           Capabilities:
               <<: *ApplicationCapabilities
   

3. I am using the default byfn.sh script to bring up the network.

But still when I try to fetch the application channel configuration block from the cli container using orderer4 envrionment, I am successfully able to do it and on decoding it to JSON file, I can see that all 4 orderers are part of the application channel's consenters section as well as every orderer's address is present in the orderer addresses section.

So, why is the application channel not starting with only first 3 orderers despite giving only those as the consenters?

Answer 1

The channel creation command must have -channelCreateTxBaseProfile argument in it and the value for the argument would be the orderer genesis profile name (here SampleMultiNodeEtcdRaft).

Also, the identity trying to execute the peer channel create command must satisfy the following ACL: /Channel/Orderer/ConsensusType (which is by default set to the following policy: /Channel/Application/Admins).