How to temporarily pause block generation on PoS `--dev` network?

[swarren12]

We are using a local --dev network to run integration-level tests as part of our CI process. Currently, we're running against client-go:v1.13.11 but would like to upgrade to a later version (e.g. v1.16.3).

In our current version it is possible to enable and disable mining via an RPC call (miner_start, miner_stop). Since moving to the Proof-of-Stake model, the mining_ operations are no longer available. Instead, it appears that they've been replaced by starting the node with the --dev.period option.

Most of the time, we are happy to create new blocks as soon as a transaction is submitted and so we are able to run the node using --dev.period 0 so that new blocks are generated immediately; however, for some of our tests we need more fine-grained control, such as ensuring that multiple transactions are included in the same block. What is the replacement for miner_start and miner_stop in the proof-of-stake model, that will allow us to temporarily enable or disable the generation of a new block?

Alternatively: if the above isn't possible - is there a way to completely disable automatic block generation and always manually create new blocks?

[jsvisa]

I think we can implement a dev_start, dev_stop to control the block producing. However, I'm not sure if this requirement is widespread and necessary.

One more thing, as the block interval in PoS is consistent(current mainnet is 12s), so if your local dev net want to align with the mainnet, I think the block interval should also keep in consistent.

[swarren12]

I think we can implement a dev_start, dev_stop to control the block producing. However, I'm not sure if this requirement is widespread and necessary.

I can't really comment on widespread, but I would say that it's necessary - at the very least, these features were considered desirable enough to have in the mining version, I don't see any obvious reason the same wouldn't be true in the PoS world? Appreciate that I'm coming at this from a somewhat biased position though!

One more thing, as the block interval in PoS is consistent(current mainnet is 12s), so if your local dev net want to align with the mainnet, I think the block interval should also keep in consistent.

Unfortunately, 12s isn't really a viable option for automated testing. We have just shy of 1000 tests using Geth, so assuming that each test only required a single block being generated, this would increase runtime by 3 hours (even setting the generation time to 1s would result in around a 15m runtime increase)!