Why there should be orderer node in hyperledger? Can the orderer node's function be transferred to Peer node?

Question

I want to ask about blockhain Hyperledger Fabric. Is it possible to let Peer nodes to do Orderer node's task which is packing the transaction into new block?

I kind of think the orderer node is kind of a redundant node since for example in Bitcoin network, the packing of the transactions into block and the verification of new transaction is solely done by the full node(miner node).

Can anyone give me justification why there should be orderer's node in the Hyperledger Fabric?

And if I were to build my project on Hyperledger network and forgo orderer node(which means the peer node will do both the verification of transaction and the packing of transaction) is it possible?

Please tell me your thoughts and ideas.

Thank you.

user_10743233 · Answer

TL;DR

HLF by design is deterministic so the orderer nodes are important. Only they participate in consensus not all peers and the blocks they produce are Final (Not prone to forks).
No you cannot make a peer orderer as well. Your network configuration for HLF must have at least one orderer to work

Hyperledger Fabric (HLF) vs Bitcoin

HLF is a private permissioned blockchain where as Bitcoin is a public permissionless blockchain. You should not expect them to work similarly.

Public blockchains

In public blockchain for example bitcoin everyone is treated equal in other words no one have special privileges you may think well miner are the ones minning block but the important point is anyone can become miner its open game no restriction on who can become miner or who can run a node etc.

Private Blockchain

In private blockchain for example HLF roles are predefined at the time of setting up and starting blockchain. Each role has certain tasks and privileges and restriction. The no of organisations peers, endorser peers, orderers, channels all are predefined and some have special privileges which no other role has like orderer whose is responsible for receiving endorsed transactions from peers and put them into blocks then these blocks are distributed to all peers. These blocks are Final.

But Why?
Private Blockchains (Like HLF) full-fill special use cases for example supply chain, B2B operations In such use cases one may want to harness positives of blockchain like transparency, auditing, provenance but may also want some sort of role based access or restrictions of certain data to certain audience public blockchains like Ethereum and bitcoin does not fit here.

Now coming toward your question

Why is there an orderer node in HLF isn't it redundant ?

No it's not redundant, HLF has deterministic consensus algorithms where as Ethereum and Bitcoin have probabilistic consensus algorithms which means there can be ledger forks. In HLF there are no Ledger forks because fork occur when two equal participants have conflict at a common point. Incase of HLF the participants are not equal as peers cannot participate in consensus process the block order set by orderers is Final. And rightfully so because for the use cases it is designed for does not want forks and want to have special roles and much much more transaction throughput.
Must must Read !

https://hyperledger-fabric.readthedocs.io/en/release-2.2/orderer/ordering_service.html#what-is-ordering

No it is not possible to assign peers orderer's role you must have at least 1 orderer in your HLF network to work.