Hyperledger composer for enterprise

Question

I saw that Hyperledger composer is really easy to work with, also we can deploy the composer code on hyperledger fabric. But I found that they create only one channel, and we will have the flexibility to talk to the specific peers like what we can do in GoLang\fabric, can we call external web services from composer java script code as we can do in Golang on fabric?

I'm wondering, can we use hyperledger composer for enterprise blockchain applications? or just we use it to create blockchain POCs.

Regards.

Bassel Kh

Answer 1

yes, you can call external web services and get the results back into your smart contract code or client see -> https://hyperledger.github.io/composer/latest/integrating/call-out

yes Hyperledger Composer is intended for Enterprise blockchain applications. Your applications will use Composer client to write application data to the ledger, and its production runtime is where the 'chaincode' smart contract/business network is deployed/installed on the peers (just like Go chaincode is similarly deployed). One such provider using Composer is here -> https://ibm-blockchain.github.io/platform-deployment/

Finally also see here -> https://github.com/hyperledger/composer-knowledge-wiki/blob/latest/knowledge.md#production for more info.

Answer 2

Hyperledger Composer is intended to be used for enterprise blockchain applications, although Composer Playground is not intended for Production use.

Composer connects with Fabric using Business Network Cards, and these contain credentials and a Connection Profile. The connection profile contains definitions of the 'services' on the Fabric, and so it is possible to define specific Peers within the card.

Regarding channels - it is again the Connection Profile that determines the Channel used, and at the moment only one channel is supported per Card. Multiple cards can be used but disconnect/switch/re-connect might not be practical or desirable in some cases. There is a way to connect to a different Business Network on a different Channel covered in this tutorial, but again it might not be suitable for all cases.

There is an outstanding issue on GitHub for using Composer for multi-channel, so you can leave a comment or +1 on it - particularly if you have a good use case for multi-channel.

Many people are thinking of and using channels as a security feature, but Composer ACLs might solve that issue in some cases. Similarly the upcoming sidedb feature in Fabric might offer security instead of separate channels.