Can multi-channels be supported by Hyperledger in one peer

Question

Is it possible to run two or more channels on the same peer container? 

Answer 1

Yes you can run  multiple chains on one peer, all you need is to produce a configuration for each one of them and make your peer to join it. Just follow the following steps: 

1. You need to provide chain configuration within [ configtx.yaml ]

2. Use [ configtxgen ] to produce create channel transaction and updates for anchor peers

configtxgen -profile PeerChannelProfile -channelID YourNewChannel -outputcreateChannelTx=newchannel.tx

where PeerChannelProfile is the configuration profile you have defined in configtx.yaml file.

Now an update is needed for anchor peers per organisations depending on he number of organisations as following:

  configtxgen -profile PeerChannelProfile -channelID YourNewChannel -outputAchorPeersUpdate=Org1MSPAnchor.tx -asOrg=Org1MSP

The above steps need to be repeated for each organisation.

3. Now when you have create channel transaction you can actually make your peer to join the network by:

peer channel create -o orderer:7050 -c YourNewChannel -f newchannel.tx

This will produce the genesis block for your channel

4. Make the peer join it:

peer channel join -o orderer:7050 -c --blockpath YourNewChannel.block

Comments

Error: got unexpected status: BAD_REQUEST -- Attempted to include a member which is not in the consortium

doesnt produce genesis block for new channel...gives the  above error.

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Try exporting channel name first:

/opt/gopath/src/github.com/hyperledger/fabric/peer# export CHANNEL_NAME=mychannel

And then run the above commands.

Answer 2

Yes, there can be multiple channels for a single peer. Channels hold applications data. Multiple channels are used to provide privacy and security.

Comments

Hey @Neeraj, thanks for the answer. You mentioned it holds the application data. What data does it hold?

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Hi @Raj, you're welcome.

Channels mainly hold user data, order data, etc.

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Hi. I have a doubt. Why would someone create two channels in a single peer?

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@Kishan

Think of a situation where there are two users. These users and some shared data and some data that they don't want the other user to see. In such case, each user will create a channel and store the private data in it so that it is not accessible to the other user.

Answer 3

Yes, Hyperledger supports multiple channels in a peer. This is actually a feature that most of the organizations use.