fix: fixing metrics views, cherry-pick (3307)

[JaydipGabani]

Signed-off-by: Jaydip Gabani gabanijaydip@gmail.com
(cherry picked from commit 71bd2a6)
This PR is CP of #3307
What this PR does / why we need it:

Which issue(s) this PR fixes (optional, using fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when the PR gets merged):
Fixes #

Special notes for your reviewer:

[sozercan]

@JaydipGabani do you mind creating a seperate pr for the protobuf cp? so it's easier to diagnose any issues

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 54.50%. Comparing base (52106aa) to head (adef5a7).

Additional details and impacted files

@@               Coverage Diff                @@
##           release-3.15    #3309      +/-   ##
================================================
+ Coverage         54.42%   54.50%   +0.08%     
================================================
  Files               134      134              
  Lines             12329    12334       +5     
================================================
+ Hits               6710     6723      +13     
+ Misses             5123     5115       -8     
  Partials            496      496              

Flag	Coverage Δ
unittests	54.50% <100.00%> (+0.08%)	⬆️

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[maxsmythe]

IIRC there was a race condition with registering metrics that was found as part of the otel migration. This caused some metrics to not be reported, especially if there were multiple exporters. Do you remember what that race condition was? Would this PR interact with that?

[JaydipGabani]

IIRC there was a race condition with registering metrics that was found as part of the otel migration. This caused some metrics to not be reported, especially if there were multiple exporters. Do you remember what that race condition was? Would this PR interact with that?

The race condition was related to GetMeterProvider getting called before the execution of SetMeterProvider in exporters. To resolve that I moved function call to GetMeterProvider within newreporter() for all reporter instead of init(). Creating views within init wouldn't introduce this race condition again. In fact it was a mistake on my part to move registering views within newrepoerter() in the first place as it was needed to properly initiate metrics through SetMeterProvider(), i.e. we need to register views before SetMeterProvider() is called.

[maxsmythe]

Thanks for the context!

[maxsmythe]

LGTM