fix: transaction per block metrics

[miazn]

Motivation

To go along with adding TCP Events received, this PR adds TCP Events sent, as well as adds the node/router plaintext Messages sent and received. edit: removed these since part of the histogram labeling was taking up unnecessary space in prometheus, and the metrics arent really needed
It also changes the transactions per block to be a gauge rather than a counter (which we already registered it as here, since a counter cannot decrease, thus fixing the transaction metrics in Grafana

[miazn]

@joske I believe we will also have to update the TPS stat in the Grafana dash, should it just be the avg() rather than the sum(rate())?

[howardwu]

@joske the intention is to calculate the number of transactions per block here. Will increment be the right operation?

[joske]

No this will add next_block.transactions().len() to the existing value of the gauge. I think you should use the metrics::gauge method, which will set the current value of transactions per block.

[miazn]

Since prometheus is a time series database, even if we set this gauge to be the existing number of transactions, it would not be per block. Since we scrape the endpoint every 15s , I'm pretty confident that we would only get the reading of the current state, i.e. we would be "missing" data from one block if blocktime is under 15 seconds.

I decided to make the metric increment because the metric name is snarkos_blocks_transactions_total and I figured this way we would capture all the data. Now, it is correct that this metric should be a counter, since it is always increasing. However, our snarkVM implementation only exposes an increment_counter function that increases by the constant 1 .

I think that this transaction metric should be a total, to reflect the metric name as well as not miss any block data. The best way to do this would be to change the increment counter function in snarkvm to take a value, rather than make it a constant, but switching the metric to a gauge was the lowest-lift method. Let me know what is preferred here.