同一组织的Hyperledger Fabric 2对等节点导致Chaincode和Couchdb问题

Question

I am facing a very strange issue with Hyperledger Fabric node.js sdk issue.

Right now, my network consists of:

a.) Single org b.) 2 peers of that org (peer0 and peer1). c.) 1 orderer d.) 1 ca

When using node.js sdk, both peers joined the channel as you can see in the code snippet below:

var fabric_client = new Fabric_Client();
var channel = fabric_client.newChannel(channelName);
var peer = fabric_client.newPeer('grpc://localhost:7051');
var peer2 = fabric_client.newPeer('grpc://localhost:8051');
channel.addPeer(peer);
channel.addPeer(peer2);
var order = fabric_client.newOrderer('grpc://localhost:7050')
channel.addOrderer(order);

I am calling a chaincode function written in golang that generates a unique id, create the hash of it (SHA256) and saves in couchdb and logs that hash to container like this:

"password":"5ef32e670c38727ce5011dad62ff1a150362433789fdd878f2623a08bbdc990b"

The issue is, when node.js sdk is configured with single peer. It saves the same hash in couchdb that log shows. But when configured with 2 peers as the above sdk code snippet shows. The logged hash and couchdb hash does not match.

I think the hash changes because 2nd peer execute the same code again in which a random string is generated and hashed.

Any help/comment would be appreciated. Thanks

Answer 1

A few things:

1) Not sure what your endorsement policy is, but assuming it is the default then generally speaking you only need to request endorsement from a single peer in the organization

2) Most importantly you should not use non-deterministic functions within your chaincode. If you actually had multiple organizations and the endorsement policy required signatures from multiple orgs, then your transaction would fail anyway (as peers from different orgs would generate different responses due to the non-deterministic unique id function you are using). In this case, since you only require a single endorsement, the state would likely be updated but it would use the value of the first response.