In Quorum, is it possible to replicate a private smart contract to a new node after the contract is deployed?

Question

This question is about Quorum. I noticed that the quorum tag is present on this site hence adding the question here. If this question should rather be asked elsewhere, please let me know.

I am exploring Quorum for a business use case. I have this peculiar situation where there is a private contract Contract X shared between Node A and Node B. A new node Node C joins the network. Node C needs to have access to the private contract Contract X which is already deployed on Node A and Node B.

Is there any way to get Contract X along with its current state on Node C?

I know that if I have access to the source code or ABI of Contract X, I can just deploy Contract X on Node C. However, as per my understanding, this will give Contract X on Node C a different address than what it has on the other nodes. So any transaction I send to all three nodes targeting Contract X with fail on Node C.

Answer 1

Answered in https://github.com/jpmorganchase/quorum/issues/552

Quorum v2.1 currently does not support this -- a private contract shared on A and B cannot be extended to node C -- we have a solution that we are working on but this is still pretty early in the pipeline.

Our recommendation for when you need to add participants is to create a new contract Z with A, B, and C nodes, move the data over through a private txn on that contract, and then finally kill the original X.