CODEWITHSUNDEEP
hyperledger-fabrichyperledger
Akshay Sood
Akshay Sood

Reputation: 6786

Hyperledger fabric peers panic due to previous block hash mismatch

I have a hyperledger fabric network with 2 organizations and 2 peers per organization. I restored the network from backup and the peers started throwing the following error:

2021-01-28 09:49:55.374 UTC [gossip.state] commitBlock -> ERRO 26b Got error while committing(unexpected Previous block hash. Expected PreviousHash = [91e8aafc47e2f521afc8a52d44b80c60fe781084dec9e1b92ab40d8b6138e7d0], PreviousHash referred in the latest block= [042c3059d75a1622fea88f7f2a5f268363206004ebca635118039e0496b83197]
github.com/hyperledger/fabric/common/ledger/blkstorage/fsblkstorage.(*blockfileMgr).addBlock
        /opt/gopath/src/github.com/hyperledger/fabric/common/ledger/blkstorage/fsblkstorage/blockfile_mgr.go:254
github.com/hyperledger/fabric/common/ledger/blkstorage/fsblkstorage.(*fsBlockStore).AddBlock
        /opt/gopath/src/github.com/hyperledger/fabric/common/ledger/blkstorage/fsblkstorage/fs_blockstore.go:42
github.com/hyperledger/fabric/core/ledger/ledgerstorage.(*Store).CommitWithPvtData
        /opt/gopath/src/github.com/hyperledger/fabric/core/ledger/ledgerstorage/store.go:132
github.com/hyperledger/fabric/core/ledger/kvledger.(*kvLedger).CommitWithPvtData
        /opt/gopath/src/github.com/hyperledger/fabric/core/ledger/kvledger/kv_ledger.go:312
github.com/hyperledger/fabric/core/ledger/ledgermgmt.(*closableLedger).CommitWithPvtData
        <autogenerated>:1
github.com/hyperledger/fabric/core/committer.(*LedgerCommitter).CommitWithPvtData
        /opt/gopath/src/github.com/hyperledger/fabric/core/committer/committer_impl.go:93
github.com/hyperledger/fabric/gossip/privdata.(*coordinator).StoreBlock
        /opt/gopath/src/github.com/hyperledger/fabric/gossip/privdata/coordinator.go:243
github.com/hyperledger/fabric/gossip/state.(*GossipStateProviderImpl).commitBlock
        /opt/gopath/src/github.com/hyperledger/fabric/gossip/state/state.go:810
github.com/hyperledger/fabric/gossip/state.(*GossipStateProviderImpl).deliverPayloads
        /opt/gopath/src/github.com/hyperledger/fabric/gossip/state/state.go:598
runtime.goexit
        /opt/go/src/runtime/asm_amd64.s:1333
commit failed
github.com/hyperledger/fabric/gossip/privdata.(*coordinator).StoreBlock
        /opt/gopath/src/github.com/hyperledger/fabric/gossip/privdata/coordinator.go:246
github.com/hyperledger/fabric/gossip/state.(*GossipStateProviderImpl).commitBlock
        /opt/gopath/src/github.com/hyperledger/fabric/gossip/state/state.go:810
github.com/hyperledger/fabric/gossip/state.(*GossipStateProviderImpl).deliverPayloads
        /opt/gopath/src/github.com/hyperledger/fabric/gossip/state/state.go:598
runtime.goexit
        /opt/go/src/runtime/asm_amd64.s:1333
github.com/hyperledger/fabric/gossip/state.(*GossipStateProviderImpl).commitBlock
        /opt/gopath/src/github.com/hyperledger/fabric/gossip/state/state.go:811
github.com/hyperledger/fabric/gossip/state.(*GossipStateProviderImpl).deliverPayloads
        /opt/gopath/src/github.com/hyperledger/fabric/gossip/state/state.go:598
runtime.goexit
        /opt/go/src/runtime/asm_amd64.s:1333)

I am not sure what went wrong but all 4 peers started throwing the error. Any suggestion on what should be done next? Thanks

Upvotes: 1

Views: 439

Answers (1)

yacovm
yacovm

Reputation: 5140

You probably backed up the network by first backing up peers and then backing up orderers.

This is dangerous because then the backup you create results in peers being at a higher block height than the orderers.

As an example, imagine the orderers have a latest backed up block 100 and the peers have a latest backed up block 101 with hash of bar. The orderers will create block 101 with hash of foo and the peers will never need to pull it. Then, the orderers will create block 102 with previous hash foo but the peers expect a previous hash of bar.

Upvotes: 2

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