前言 社区里在讨论一个问题，是由官方的文档引发的，文档上讲不同的peer可以使用不同语言的链码，前提是2份链码功能、接口等必须一致。
大家的问题是：
一个链码可以采用不同的语言实现，不同peer上使用不同的链码真的可行吗？
经过实证，这是不可行的。
分2种情况，2种都有问题：
不同peer安装不同语言链码，然后同时实例化：实例化后，只能启动发送实例化交易的peer拥有的语言的链码
部分peer先实例化，另外peer再安装不同语言链码：调用链码时报指纹不匹配错误
不同peer安装不同语言链码，然后同时实例化 1、修改BFYN，只在peer0.org1和peer0.org2上安装Go语言链码，不进行后续操作。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Installing chaincode on peer0.org1... + peer chaincode install -n mycc -v 1.0 -l golang -p github.com/chaincode/chaincode_example02/go/ + res=0 + set +x 2019-09-03 02:08:43.813 UTC [chaincodeCmd] checkChaincodeCmdParams -> INFO 001 Using default escc 2019-09-03 02:08:43.813 UTC [chaincodeCmd] checkChaincodeCmdParams -> INFO 002 Using default vscc 2019-09-03 02:08:44.108 UTC [chaincodeCmd] install -> INFO 003 Installed remotely response:<status:200 payload:"OK" > ===================== Chaincode is installed on peer0.org1 ===================== Install chaincode on peer0.org2... + peer chaincode install -n mycc -v 1.0 -l golang -p github.com/chaincode/chaincode_example02/go/ + res=0 + set +x 2019-09-03 02:08:44.260 UTC [chaincodeCmd] checkChaincodeCmdParams -> INFO 001 Using default escc 2019-09-03 02:08:44.260 UTC [chaincodeCmd] checkChaincodeCmdParams -> INFO 002 Using default vscc 2019-09-03 02:08:44.529 UTC [chaincodeCmd] install -> INFO 003 Installed remotely response:<status:200 payload:"OK" > ===================== Chaincode is installed on peer0.org2 ===================== ========= All GOOD, BYFN execution completed ===========
2、在peer1.org1上安装Java语言链码
1 2 3 4 root@6cec20eb7502:/opt/gopath/src/github.com/hyperledger/fabric/peer# peer chaincode install -n mycc -v 1.0 -l java -p /opt/gopath/src/github.com/chaincode/chaincode_example02/java/ 2019-09-03 03:19:44.710 UTC [chaincodeCmd] checkChaincodeCmdParams -> INFO 001 Using default escc 2019-09-03 03:19:44.711 UTC [chaincodeCmd] checkChaincodeCmdParams -> INFO 002 Using default vscc 2019-09-03 03:19:44.754 UTC [chaincodeCmd] install -> INFO 003 Installed remotely response:<status:200 payload:"OK" >
3、在peer1.org1上发起实例化链码
1 2 3 root@6cec20eb7502:/opt/gopath/src/github.com/hyperledger/fabric/peer# peer chaincode instantiate -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 -l golang -v 1.0 -c '{"Args":["init","a","100","b","200"]}' -P 'OR ('\''Org1MSP.peer'\'','\''Org2MSP.peer'\'')' 2019-09-03 03:22:12.430 UTC [chaincodeCmd] checkChaincodeCmdParams -> INFO 001 Using default escc 2019-09-03 03:22:12.431 UTC [chaincodeCmd] checkChaincodeCmdParams -> INFO 002 Using default vscc
4、查看链码容器，只有peer1.org1的链码容器，peer0.org1和peer0.org2的链码容器都没有起来。
1 2 3 4 5 6 7 8 9 ➜ fabric-sdk-go-sample git:(master) ✗ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES f8f6aa8b5da6 dev-peer1.org1.example.com-mycc-1.0-cd123150154e6bf2df7ce682e0b1bcbea40499416f37a6da3aae14c4eb51b08d "/root/chaincode-jav…" 37 seconds ago Up 36 seconds dev-peer1.org1.example.com-mycc-1.0 6cec20eb7502 hyperledger/fabric-tools:latest "/bin/bash" About an hour ago Up About an hour cli 7e134fe7e8e9 hyperledger/fabric-peer:latest "peer node start" About an hour ago Up About an hour 0.0.0.0:8051->8051/tcp peer1.org1.example.com ed6f5511d938 hyperledger/fabric-peer:latest "peer node start" About an hour ago Up About an hour 0.0.0.0:10051->10051/tcp peer1.org2.example.com 025a71178777 hyperledger/fabric-peer:latest "peer node start" About an hour ago Up About an hour 0.0.0.0:7051->7051/tcp peer0.org1.example.com 8687dfd14e7b hyperledger/fabric-peer:latest "peer node start" About an hour ago Up About an hour 0.0.0.0:9051->9051/tcp peer0.org2.example.com e9cc8b410d7f hyperledger/fabric-orderer:latest "orderer" About an hour ago Up About an hour 0.0.0.0:7050->7050/tcp orderer.example.com
部分peer先实例化，另外peer再安装不同语言链码 不改造BYFN，原生启动。peer0.org1，peer0.org2，peer1.org2都已经实例化了Go语言链码。
然后在peer1.org1上安装Java语言的链码，在执行Invoke或者查询，报指纹不匹配-数据不匹配的错误。
原因分析：操作链码时，会调用LSCC的LifeCycleSysCC.getCCCode获取链码，一份链码是从数据库取的，即当前链码容器的，一份链码是本地存储的，会对2份进行匹配，如果不匹配就会报指纹不匹配错误。
匹配函数为CDSPackage.ValidateCC，匹配项为：
名称、版本
CodeHash、元数据Hash
调用链码时报的指纹不匹配错误：
1 2 3 4 5 6 7 8 9 10 11 12 13 root@d0533ffe1864:/opt/gopath/src/github.com/hyperledger/fabric/peer# peer chaincode install -n mycc -v 1.0 -l java -p /opt/gopath/src/github.com/chaincode/chaincode_example02/java/ 2019-09-03 01:52:15.714 UTC [chaincodeCmd] checkChaincodeCmdParams -> INFO 001 Using default escc 2019-09-03 01:52:15.714 UTC [chaincodeCmd] checkChaincodeCmdParams -> INFO 002 Using default vscc 2019-09-03 01:52:15.755 UTC [chaincodeCmd] install -> INFO 003 Installed remotely response:<status:200 payload:"OK" > root@d0533ffe1864:/opt/gopath/src/github.com/hyperledger/fabric/peer# root@d0533ffe1864:/opt/gopath/src/github.com/hyperledger/fabric/peer# root@d0533ffe1864:/opt/gopath/src/github.com/hyperledger/fabric/peer# root@d0533ffe1864:/opt/gopath/src/github.com/hyperledger/fabric/peer# root@d0533ffe1864:/opt/gopath/src/github.com/hyperledger/fabric/peer# peer chaincode query -C mychannel -n mycc -c '{"Args":["query","a"]}' Error: endorsement failure during query. response: status:500 message:"failed to execute transaction b8b740aab0e6dd10cfe62416240ef94bfb90a55358904233c4d60dd5a39e6fe3: [channel mychannel] failed to get chaincode container info for mycc:1.0: could not get chaincode code: chaincode fingerprint mismatch: data mismatch" root@d0533ffe1864:/opt/gopath/src/github.com/hyperledger/fabric/peer# root@d0533ffe1864:/opt/gopath/src/github.com/hyperledger/fabric/peer# 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 peer1.org1.example.com:8051 --tlsRootCertFiles /opt/gopath/src/github.com/hyperledger/fabric/peer/crypto/peerOrganizations/org1.example.com/peers/peer1.org1.example.com/tls/ca.crt -c '{"Args":["invoke","a","b","50"]}' Error: endorsement failure during invoke. response: status:500 message:"failed to execute transaction aec5a0ccbcf86032774dc80220b90419d2816cc3f050a104c1cfcde55a2247cb: [channel mychannel] failed to get chaincode container info for mycc:1.0: could not get chaincode code: chaincode fingerprint mismatch: data mismatch"
文章 另外，社区里的hucg编写了一篇源码文章：https://blog.csdn.net/love_feng_forever/article/details/100532324
