Implement missed block store (or completely remove them as a metric?)

[faustbrian]

Is your feature request related to a problem? Please describe.
In 2.3 we drop the wallets table from the database as we haven't been using it since the release of 2.0 in November 2018 which means we no longer store missed and produced blocks. This results skewed missed blocks and productivity via public API.

Describe the solution you'd like
Basically something like the state storage in core-blockchain but for missed blocks. We could keep the data in-memory and then dump it on shutdown with something like https://github.com/typicode/lowdb as the size of the data would be very small.

Describe alternatives you've considered

1. Keeping the wallets table, which is irrational as missed blocks and productivity are just arbitrary values without any real meaning or use for consensus.
2. Completely removing missed blocks and productivity because as mentioned before they are just arbitrary values without any use for consensus.

[dated]

From alessio / fun:

I would personally favour the 2nd proposed alternative. As noted in the issue, they are arbitrary and meaningless numbers that play no role in consensus but what's more, they are a psychological DDoS risk. By that, I mean someone may be incentivised to purposely try targeting highly productive delegates just to sabotage their statistics and productivity rankings. I run the top two most productive delegates on mainnet and I am constantly paranoid that someone will try attacking my nodes purely because of that, especially because actually doing so is really easy, so I would welcome their removal to take the target off of my back. Moreover if there is a network outage or bugs in the core that result in missed blocks then it's not really fair for a delegate to take a hit in that regard either as it makes them look like bad operators when it's not their fault, so all in all I would be in favour of the second alternative in the issue to scrap missed blocks and productivity counters altogether. I hope you'll seriously consider it.

[faustbrian]

Agree with all of that, pretty much my initial thoughts when I made plans to remove the wallets table.

Downtimes caused by bugs or attacks are not the fault of a node maintainer and especially from v1 days some people might look like bad maintainers while it was simply software bugs that caused the downtimes.

If more people share that opinion I will remove the relics of all productivity related code.

[dated]

In favour of removing here 👋

[samharperpittam]

I'm in agreement here too

[roks0n]

+1 for removing

[moazzamak]

+1, should be removed

[faustbrian]

Resolved by #2257

[geopsllc]

I still think we need some kind of metric of how reliable a delegate is. Might not be that applicable to ARK atm but it's very handy for forks.