Feature request: ability to track number of requests made

[extemporalgenome]

Related to controlling pagination via #231, it would be useful to known how many top-level DynamoDB requests were made as part of a high-level operation. Typically this would be for queries/scans (how many sequential pages were fetched?), though potentially it could also apply to BatchWriteItem or BatchReadItem calls.

Perhaps this could live in ConsumedCapacity.

It's unclear if there's value in distinguishing between planned-for requests and actual requests, in order to account for retries due to throttling, etc. Retries could also be tracked explicitly, of course.

[guregu]

Good idea, I think we can shove it into ConsumedCapacity

[guregu]

This is next on my to-do list, it will be helpful for testing once it's in. ETA this weekend.

[guregu]

Sorry, got distracted by some other stuff ;)
Still at the top of the TODO list

BTW, do you think it should count for every request "attempt" or every "successful request"? I'm thinking attempts.
Example: query -> throttled -> retry query = 2 requests

[guregu]

Just released v2.1.0 which includes a Requests field in ConsumedCapacity. It's not perfect (see #241) but it will get you most of the way there.

[extemporalgenome]

Awesome, thanks! I figure, in terms of retries, we might want to track semantic requests (i.e. a page of query results) vs low-level requests separately. iow, if you fetch 5 pages of results, but one of those pages needed to be tried twice, then it'd be useful to distinguish that there were 5 total pages, but 6 total requests.

I could see that being distinguished by the addition of a Pages counter, which only tracks original outgoing requests (not retries), at which point Requests could get hooked into that SDK middleware. Alternatively, a Retries counter could be added, and would stay zero unless retries were made; at that point, to infer "Pages", it'd be Requests - Retries.