[Gemini] Prototype OpenAI RemoteInferenceModelHandler Implementation

[jrmccluskey]

Experimental codegen implementation of an OpenAI RemoteInferenceModelHandler in the Python SDK. As is the case with the Java implementation, the IT test will not run as part of CI because beam does not have an OpenAI API key secret.

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R: @claudevdm for label python.

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[claudevdm]

Should we set a default max batch size so that we dont exceed the api batch size limits?

[jrmccluskey]

Test failures are still the Bigtable issues

[claudevdm]

I believe RunInference shares the client between harness threads so once a batch is done this helper closes all of the client's connections that other threads are waiting on?

Maybe we should we go back to the regular OpenAI client and use a small thread pool to send the prompts at the same time? Or, if you'd rather stay async, create the client inside each batch like the vLLM handler does?

[jrmccluskey]

flipped back to sync client

[codecov]

Codecov Report

❌ Patch coverage is 0% with 104 lines in your changes missing coverage. Please review.
✅ Project coverage is 55.15%. Comparing base (b849208) to head (edee7f0).
⚠️ Report is 191 commits behind head on master.

Files with missing lines	Patch %	Lines
...ython/apache_beam/ml/inference/openai_inference.py	0.00%	104 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #40239      +/-   ##
============================================
- Coverage     56.09%   55.15%   -0.94%     
+ Complexity     2284     1722     -562     
============================================
  Files          1120     1079      -41     
  Lines        176909   173143    -3766     
  Branches       1475     1262     -213     
============================================
- Hits          99244    95505    -3739     
- Misses        75147    75362     +215     
+ Partials       2518     2276     -242     

Flag	Coverage Δ
python	79.56% <0.00%> (-0.27%)	⬇️

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[jrmccluskey]

@claudevdm bump