Hyperledger v1.0频道

Question

In Hyperledger 1.0 could I share ledger between channels? For example, if I want to create 2 channels, one for reading and the other for writing (it's like access control), how could I synchronize the ledgers if every channel has its own ledger. is there any other solution? Thank you

Answer 1

You say that you want to use channels for flow control. This is not what channels are for. They are a construct modelling a sub-chain for privacy purposes. A channel exists on a specified set of peers and runs chaincode or chaincodes that are relevant to the channel's purpose (often a set of transactions between specific participants that require privacy).

Flow control, on the other hand, is required on a single channel and chaincode combination as key clashes in the same database partition are fatal to a transaction. A key clash happens when a transaction in a block is trying to commit a change to a key that a previous transaction in the same block has already changed. The transaction is immediately failed and that is recorded in the block.

EDIT : The late failure is NOT recorded in the block in any way that I can find, however you do get notified through the event hub of the MVCC failure. Hyperledger Composer conveniently sends you this notification in the catch block of the "transaction" SDK call.

To get around that, a chaincode should avoid using convenience keys to record status etc because every transaction then comes into conflict. In addition, adding flow control for asset keys is a great idea in that you really want to send changes to a specific asset only when there are no outstanding transactions against that asset. A queue can be used to smooth out the flow in case of a burst of activity.