What is the impact of stopping a chaincode container of a peer?

We know that if a Peer has chaincode installed, it will run it as chaincode container to help the channel to perform a transaction on the chaincode.

If you stop a chaincode container of a peer who is not a required member of the chaincode, the chaincode will continue to work.

Let's use the BYFN network as an example to find out the impact of stopping a chaincode container of a peer.

1. List all running chaincode containers:

$ docker ps | grep chaincode

CONTAINER ID  STATUS       NAMES
f729e3534a17  Up 14 hours  dev-peer1.org2.example.com-mycc-1.0
9b93813390d3  Up 14 hours  dev-peer0.org1.example.com-mycc-1.0
4e1b1b131dc5  Up 14 hours  dev-peer0.org2.example.com-mycc-1.0

This matches well with what we learned on the CLI container. All 4 peers are members of "mychannel", but only 3 peers have "mycc" chaincode installed and running.

2. Stop the chaincode container for peer1.org2:

$ docker stop f729e3534a17

3. Check the chaincode status on peer1.org2. No changes.

$ docker exec -it cli bash

bash-4.4# source peer1-org2.sh
bash-4.4# peer chaincode list --installed
   Get installed chaincodes on peer:
   Name: mycc, Version: 1.0, Path: github.com/chaincode/chaincode_example02/...
bash-4.4# peer chaincode list -C mychannel --instantiated
   Get instantiated chaincodes on channel mychannel:

4. Submit a transaction on peer0.org1:

bash-4.4# source peer0-org1.sh

bash-4.4# peer chaincode invoke -o orderer.example.com:7050 --tls true \
   --cafile /opt/gopath/src/github.com/hyperledger/fabric/peer/crypto\
   /ordererOrganizations/example.com/orderers/orderer.example.com/msp\
   /tlscacerts/tlsca.example.com-cert.pem -C mychannel -n mycc \
   --peerAddresses peer0.org1.example.com:9051 --tlsRootCertFiles \
   /opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/peerOrganizations\
   /org1.example.com/peers/peer0.org1.example.com/tls/ca.crt \
   --peerAddresses peer0.org2.example.com:9051 --tlsRootCertFiles \
   /opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/peerOrganizations\
   /org2.example.com/peers/peer0.org2.example.com/tls/ca.crt \
   -c '{"Args":["invoke","a","b","10"]}'
[chaincodeCmd] chaincodeInvokeOrQuery -> INFO 001 Chaincode invoke successful. result: status:200

bash-4.4# peer chaincode query -C mychannel -n mycc -c '{"Args":["query","a"]}'
80

5. Verify that the status chaincode container for peer1.org2 is still stopped.

bash-4.4# exit

$ docker ps | grep chaincode
CONTAINER ID  STATUS       NAMES
9b93813390d3  Up 14 hours  dev-peer0.org1.example.com-mycc-1.0
4e1b1b131dc5  Up 14 hours  dev-peer0.org2.example.com-mycc-1.0

The logical chaincode instance "mycc" on the channel is still working without the chaincode container for peer1.org2, because peer1.org2 is not a required peer for the chaincode.

⇒ Auto-Start of Required Chaincode Container

⇐ Not All Member Peers Run Chaincode

⇑ Hyperledger Fabric Docker Containers

⇑⇑ Hyperledger Tutorials