Report duration of failed retrievals

[bajtos]

At the moment, most retrievals (>99.99%) fail. We are not measuring the duration of failed retrievals, and therefore we don't know how many tasks can an honest checker node complete every round.

Let's start collecting that data.

• [ ] Modify spark checker to report duration for failed retrievals too.

  Note: we should be collecting this data, but apparently, some measurements come with an invalid end_at value. See https://github.com/filecoin-station/spark/issues/43#issuecomment-1832146304

  Let's ensure end_at is always set correctly.

• [ ] Modify spark-evaluate to produce two retrieval stats - duration of successful requests and duration of all requests.

• [x] Figure out how to handle measurements with end_at set to Date(0) - they are clearly invalid, but why are we receiving them? Are they produced by fraudulent nodes?

[bajtos]

Oh! We don’t have any catch block, that’s why we are not setting end_at. And I am guessing that PG or node-pg converts null to Date(0).

https://github.com/filecoin-station/spark/blob/a6098496c67d016794dd98af5b08d33bcf6e8157/lib/spark.js#L97-L99

See also https://github.com/filecoin-station/spark/issues/43#issuecomment-1832209200

[bajtos]

Figure out how to handle measurements with end_at set to Date(0) - they are clearly invalid, but why are we receiving them? Are they produced by fraudulent nodes?

This will be fixed by https://github.com/filecoin-station/spark-api/pull/160