Quote from: DaveF on Today at 12:15:17 AM

Quote from: PrimeNumber7 on July 26, 2021, 12:37:41 AM

...
The only reason why two nodes would not be in agreement is if one node received a block but another did not. It would not make sense to mine an empty block if you are not mining on top of a newly found block because you have already validated that the previous block was valid.

Remember dozens of farms and mining nodes spread out all over. You really want them to be in sync. Mostly because they are paying PPS.
Keep in mind in a PPLNS pool an orphan sucks but it costs the pool their fee and not much more.

For the big Chinese pools that tend to put out the most 0 transaction blocks, their miners are PPS so if the pool looses a block it costs them money because the miners get paid no matter what.

So you submit the block with 0 transactions and get the BTC because not doing it costs you money.

-Dave

Think about why two nodes belonging to a miner might be out of sync.

One possibility is that one node thinks the most recent block is 692827, and this block's hash is 0000000000000000000aa...5d17c6d2 while another node thinks the most recent block is 692827 and that block's hash is 0000...c5d17d6f3. Assuming both blocks are valid, the miner would need to make a decision as to which block they are going to mine on top of, and assuming each block has a different set of transactions, including zero transactions in a block on top of either block will not prevent any new block from being invalid.

Another possibility is that one node thinks the most recent block is 692827, and this block's hash is 0000000000000000000aa...5d17c6d2 while another node thinks the most recent block is 692826 and that block's hash is 000000000000000000011...0025b5c48. If this was the case, one of the nodes simply has not yet received block 692827, and assuming the miner can trust the block is valid, it can mine on top of it with transactions if it has updated its list of unspent outputs. If the miner were to start mining an empty block in this scenario, it would need to choose which block to mine on top of -- mining on top of 826 would likely result in an orphaned block, while mining on top of 827 would result in the block being accepted provided it is otherwise valid and is propagated prior to any other miner propagating their own block on top of 827.

In both scenarios, the miner does not actually reduce the risk of having their found block be invalid. If anything, a miner with two nodes can start mining on top of a newly found block more quickly, as it can start doing so once the node receives (and validates) a block.

The only scenario in which mining an empty block would be +EV would be if the miner has received a new block, and has not yet updated their list of unspent outputs, so it cannot know which transactions are valid that can be included in a new block. One might also argue that mining an empty block would be +EV if the transaction fees are very low, but that is not the case currently. I noted above that a miner might validate a block prior to updating the unspent output table to allow it to start mining on top of a new block more quickly, so mining an empty block does not necessarily mean it is SPV mining.