serialize each datapoint into separate line

[sahejsingh]

Description: Dynatrace API api expects each metric and its value to be on a separate line.

I might be wrong here, but to me it looks like the Dynatrace exporter incorrectly concatenates multiple data points for a single metric into one line. When this one line exceeds 2000 chars, the dynatrace server returns an error.

This change changes the way a DataPointSlice is serialized.

Now each data data point is serialised into its own line. The chunking later on can easily break this into 1000 lines (as required by the api).

versions:
otel library (used by client app): v0.17.0
otel-collector: 0.21.0
dynatrace: 1.211.111.20210222-093946

Link to tracking Issue: none.

Testing: unit testing and also able to push the metrics to a live instance of dynatrace server.

Documentation: none.

[linux-foundation-easycla]

The committers are authorized under a signed CLA.

• ✅ Sahejpreet Singh (2e9c7c6aec213a5dd6fc8f3cc3e08be11546ec37, 7d6d4c8d9ed577a7e716c9bb296b86a8ee1b545a, ad559df2e141ea9d8c6c0f94fc9e4bf3dba85e9a)

[codecov]

Codecov Report

Merging #2618 (e88c487) into main (047b1d9) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #2618      +/-   ##
==========================================
+ Coverage   91.47%   91.48%   +0.01%     
==========================================
  Files         439      439              
  Lines       21855    21858       +3     
==========================================
+ Hits        19991    19996       +5     
+ Misses       1394     1392       -2     
  Partials      470      470              

Flag	Coverage Δ
integration	69.18% <ø> (-0.07%)	⬇️
unit	90.40% <100.00%> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
exporter/dynatraceexporter/metrics_exporter.go	86.66% <100.00%> (+0.39%)	⬆️
...r/dynatraceexporter/serialization/serialization.go	100.00% <100.00%> (ø)
processor/groupbytraceprocessor/event.go	96.77% <0.00%> (+0.80%)	⬆️
receiver/carbonreceiver/transport/tcp_server.go	68.00% <0.00%> (+1.00%)	⬆️

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[arminru]

Thank you, @sahejsingh!

[bogdandrutu]

@arminru @sahejsingh I cannot merge this until CLA is signed sorry.

[sahejsingh]

@bogdandrutu CLA signed 👍

[bogdandrutu]

@sahejsingh now the most important part, fix the build :)) Most likely run make gotidy or just make to see the errors

[sahejsingh]

ah, I should have paid more attention. Will fix it now.

[sahejsingh]

@bogdandrutu all checks have passed!