Feat; add a duration column for benchmark_request's

[Jamesbarford]

Adds a duration_ms column to the benchmark_request table. It takes the difference from the latest completed_at and the earliest started_at from jobs associated with the request. This column is populated when marking a request as completed.

[Kobzol]

This has to be done with some other way, right? This would just take a look at the largest completed_at and oldest started_at in the job queue, regardless of the benchmark_request(s) that we're completing. Maybe we can do it in two steps? First finish the requests, and then fill in the duration for the steps that were completed, but have no duration set yet.

[Jamesbarford]

Yes you're right the query is incorrect. I think we can add;

WHERE benchmark_request.tag = $<the_tag>

Then we will only get the jobs associated with the request. Which means we can keep it as one query.

[Jamesbarford]

37b3460

[Jamesbarford]

fceeab8 I've simplified it further, all it needs is the WHERE not the LEFT JOIN

[Kobzol]

Ah, I forgot that we try to finish a specific tag, I was somehow assuming that we just finish all requests that are done, but that's no longer the case. Yeah, looks good! Could you please add a test?

[Jamesbarford]

I forgot that we try to finish a specific tag, I was somehow assuming that we just finish all requests that are done

We are doing this as this function is called inside a loop in the cron job. Just we're not doing it as one query (though we could, with some effort, probably do that in 1 query).

For the test I've modified a pre-existing one; 030948b.

Ideally we'd add roughly 3 requests, add 3 jobs per request, mark 2 of the requests as complete, modify the dates for started_at and completed_at per job belonging to the completed requests and then assert the duration_ms is set as expected for the 2 completed requests and that the duration_ms is NULL for the in_progress job. I can't see how we can do something like this with our current setup however.