Unfortunately Fabric doesn't have this feature yet... you can comment in the JIRA that it's needed for you, but I am skeptic that we'll have this feature anytime soon

If you are willing to use your own Fabric build with custom modifications, I can point you to a PoC that adds 2 methods to the chaincode shim API:

        P2PSend(payload []byte, to ... string)
        P2PRecv() (payload []byte, from string)


However, this PoC is experimental.



From:        "Kimheng SOK" <sok.kimheng@...>
To:        Yacov Manevich <YACOVM@...>
Cc:        hyperledger-fabric@...
Date:        01/30/2020 02:55 AM
Subject:        [EXTERNAL] Re: [Hyperledger Fabric] Peer communication during chaincode execution
Sent by:        fabric@...

---

Hi,

My usecase is chaincode need to call external program, in the case of multiple peers, each peer could produce non-deterministic result and the invoke function will return Error: Could not assemble transaction. So all peers need to communicate with each other about the result and compute deterministic result so that the error will not happen. 

This feature could open the possibility to avoid all peers just passively receiving the deterministic result from a client or central entity.
For sure the computation time will increase, because the more peers we have, the more communication need to be done just like gossip protocol. So it is a trade-off .
The good news is hyperledger is a permission blockchain, so the number of peers is limited depend on the use case, so some applications could be useful to have this feature.

Bests,


On Thu, Jan 30, 2020 at 6:14 AM Yacov Manevich <YACOVM@...> wrote:
See https://jira.hyperledger.org/browse/FAB-11980

May I ask why do you need it? what's your use case?



From:        "Kimheng SOK" <sok.kimheng@...>
To:        hyperledger-fabric@...
Date:        01/29/2020 11:57 PM
Subject:        [EXTERNAL] [Hyperledger Fabric] Peer communication during chaincode execution
Sent by:        fabric@...

---

Dear all,

I wonder is it possible for peers to pass message to each other on the channel during the chaincode execution in the context of chaincode developer level not the protocol level? Or we need to modify the gossip protocol it self.

Appreciate for answering the question.

See https://jira.hyperledger.org/browse/FAB-11980

May I ask why do you need it? what's your use case?



From:        "Kimheng SOK" <sok.kimheng@...>
To:        hyperledger-fabric@...
Date:        01/29/2020 11:57 PM
Subject:        [EXTERNAL] [Hyperledger Fabric] Peer communication during chaincode execution
Sent by:        fabric@...

---

Dear all,

I wonder is it possible for peers to pass message to each other on the channel during the chaincode execution in the context of chaincode developer level not the protocol level? Or we need to modify the gossip protocol it self.

Appreciate for answering the question.

Hi,

 

I’m having issues in this tutorial and I’m not sure why or how to resolve it. I follow every step exactly but when in bash I enter the command:

 

#peer channel create -o orderer.example.com:7050 -c $CHANNEL_NAME -f ./channel-artifacts/channel.tx --tls --cafile /opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/ordererOrganizations/example.com/orderers/orderer.example.com/msp/tlscacerts/tlsca.example.com-cert.pem

 

After I enter it, I get this error:

 

2020-01-29 22:46:13.000 UTC [channelCmd] InitCmdFactory -> INFO 001 Endorser and orderer connections initialized

2020-01-29 22:46:13.019 UTC [cli.common] readBlock -> INFO 002 Expect block, but got status: &{NOT_FOUND}

2020-01-29 22:46:13.022 UTC [channelCmd] InitCmdFactory -> INFO 003 Endorser and orderer connections initialized

2020-01-29 22:46:13.452 UTC [cli.common] readBlock -> INFO 004 Expect block, but got status: &{SERVICE_UNAVAILABLE}

2020-01-29 22:46:13.455 UTC [channelCmd] InitCmdFactory -> INFO 005 Endorser and orderer connections initialized

2020-01-29 22:46:13.656 UTC [cli.common] readBlock -> INFO 006 Expect block, but got status: &{SERVICE_UNAVAILABLE}

2020-01-29 22:46:13.662 UTC [channelCmd] InitCmdFactory -> INFO 007 Endorser and orderer connections initialized

2020-01-29 22:46:13.863 UTC [cli.common] readBlock -> INFO 008 Expect block, but got status: &{SERVICE_UNAVAILABLE}

2020-01-29 22:46:13.867 UTC [channelCmd] InitCmdFactory -> INFO 009 Endorser and orderer connections initialized

2020-01-29 22:46:14.069 UTC [cli.common] readBlock -> INFO 00a Expect block, but got status: &{SERVICE_UNAVAILABLE}

2020-01-29 22:46:14.073 UTC [channelCmd] InitCmdFactory -> INFO 00b Endorser and orderer connections initialized

2020-01-29 22:46:14.275 UTC [cli.common] readBlock -> INFO 00c Expect block, but got status: &{SERVICE_UNAVAILABLE}

2020-01-29 22:46:14.278 UTC [channelCmd] InitCmdFactory -> INFO 00d Endorser and orderer connections initialized

2020-01-29 22:46:14.480 UTC [cli.common] readBlock -> INFO 00e Expect block, but got status: &{SERVICE_UNAVAILABLE}

2020-01-29 22:46:14.484 UTC [channelCmd] InitCmdFactory -> INFO 00f Endorser and orderer connections initialized

2020-01-29 22:46:14.687 UTC [cli.common] readBlock -> INFO 010 Received block: 0

 

Could you please help me resolve this? I would like to continue with the tutorials but this error is preventing me from going forward.

 

 

Kind Regards,

 

Erika Salmon

 

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