rename DoubleSum -> Sum

[codeboten]

Description:
Continuing the work started in updating OTLP to v0.8.0, DoubleSum is now Sum

Link to tracking Issue: Part of #3534

[bogdandrutu]

I think we should split this:

1. Changes in cmd/mdatagen
2. Changes in pdata (and their usages)
3. Changes in internal/goldendata

If possible :)

[bogdandrutu]

After looking at the PR only changes in the internal/goldendata about the pict files worries me a bit, if these can be separated and discuss more we can move forward with what we have here

[codeboten]

After looking at the PR only changes in the internal/goldendata about the pict files worries me a bit, if these can be separated and discuss more we can move forward with what we have here

Happy to remove the changes to pict files, are there steps to regenerate them automatically documented anywhere?

[bogdandrutu]

@codeboten I am useless here, see https://github.com/open-telemetry/opentelemetry-collector/issues/3378 where I asked the same :))

[codeboten]

fwiw, I ran

pict ./testdata/pict_input_metrics.txt > testdata/generated_pict_pairs_metrics.txt 

With the data in this PR and the output matched this PR. Note that there is an existing discrepancy in the data fixed in #3587

[bogdandrutu]

Ok my point was that I don't think we should do this change since, the Sum will have 2 possible values (Int or Double). So for this is good to keep Double in the name to signal that Sum will have Double values in the NumberDataPoint.

[codeboten]

Ah I see. Thanks for clarifying!

[codeboten]

pict changes reverted.

[bogdandrutu]

Unfortunately I cannot merge this because the upgrade of the contrib for otel-trace changes is blocked. To not waste time let's start address other issues in the meantime.

One PR that we can do is to have the conversion of IntHistogram to Histogram. We need to call this code every time when we unmarshal metrics so all the components will be able to ignore IntHistograms and we can delete them.

I am proposing this PR until we unblock the contrib upgrade. What do you think?

[bogdandrutu]

LGTM but blocking because of contrib not being able to be upgraded because of otel-trace issues.

[codeboten]

One PR that we can do is to have the conversion of IntHistogram to Histogram. We need to call this code every time when we unmarshal metrics so all the components will be able to ignore IntHistograms and we can delete them.

Sounds like a good next step @bogdandrutu, I've also got the PRs to rename DoubleGauge ready to go once the DoubleSum PRs are merged.