With Ethereum, gas is an anti-denial of service measure. What is the equivalent in Hyperledger Fabric to avoid abuse of chaincode invocation transactions (INVOKE)? Is the NVP expected to check this abuse?
From what I understood, there is no need for such a gas system in Hyperledger Fabric.
The blockchain is supposed to work in a "private" mode, meaning that you know the other peers in the network. It would be easy to detect a malicious peer and revoke its access. Also, there is no "mining" process, only consensus rules triggered for each incoming transaction. This results in a lighter block generation process compared to Bitcoin or Ethereum for example.
However, you can still implement your own custom gas system with a chaincode that add some kind of "transaction fee" before validating any Invoke transaction, but I don't think it would be possible to "mine" gas in the current state of the project.