feat(async-search): fetch fractions one by one to avoid global lock

[eguguchkin]

Fixes #423

---

• I have read and followed all requirements in CONTRIBUTING.md;
• I used LLM/AI assistance to make this pull request;

[codecov-commenter]

Codecov Report

❌ Patch coverage is 69.38776% with 30 lines in your changes missing coverage. Please review.
✅ Project coverage is 70.60%. Comparing base (03b2cad) to head (3a125af).

Files with missing lines	Patch %	Lines
frac/sealed.go	21.42%	10 Missing and 1 partial ⚠️
asyncsearcher/async_searcher.go	62.50%	6 Missing and 3 partials ⚠️
frac/remote.go	20.00%	3 Missing and 1 partial ⚠️
fracmanager/fraction_registry.go	83.33%	3 Missing ⚠️
skipmaskmanager/skip_mask_manager.go	75.00%	1 Missing and 1 partial ⚠️
storeapi/grpc_async_search.go	0.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #424      +/-   ##
==========================================
- Coverage   70.62%   70.60%   -0.02%     
==========================================
  Files         219      219              
  Lines       16970    17009      +39     
==========================================
+ Hits        11985    12010      +25     
- Misses       4089     4101      +12     
- Partials      896      898       +2     

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[github-actions]

🔴 Performance Degradation

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Name	Previous	Current	Ratio	Verdict
MutexListAppend-4	e0cf43	edfbf5
	218.29 MB/s	196.97 MB/s	0.90	🔴

[eguguchkin]

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[eguguchkin]

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[eguguchkin]

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[eguguchkin]

@seqbenchbot help

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[github-actions]

🔴 Performance Degradation

Some benchmarks have degraded compared to the previous run.
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Name	Previous	Current	Ratio	Verdict
AggWide/size=1000000-4	e0cf43	fead3d
	471.00 B/op	553.00 B/op	1.17	🔴
MutexListAppend-4	e0cf43	fead3d
	218.29 MB/s	193.26 MB/s	0.89	🔴
	74001822.00 ns/op	82790304.00 ns/op	1.12	🔴

[eguguchkin]

@seqbenchbot down be6c3c1d

[seqbenchbot]

Nice, @eguguchkin <(-^,^-)=b!

The benchmark with identificator be6c3c1d was finished.
I've prepared a summary for you. Click on Show summary button to see it:

Show summary

Query	Type	mean (ms)			stddev (ms)			p(50) (ms)			p(95) (ms)			p(99) (ms)			iterations
		base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff
bulk	warm	63.79	64.28	+0.76%	21.81	21.20	-2.81%	58.00	59.00	+1.72%	104.00	104.00	0.00%	151.00	147.00	-2.65%	39543.00	39670.00	+0.32%
service:payment-backend-eu AND k8s_namespace:prod AND level:[0 to 3] AND ( message:'failed' OR message:'timeout' )	warm	60.86	61.54	+1.11%	19.96	19.56	-1.98%	55.00	56.00	+1.82%	97.00	100.00	+3.09%	141.50	144.50	+2.12%	8086.00	8118.00	+0.40%

Have a great time!

[github-actions]

🔴 Performance Degradation

Some benchmarks have degraded compared to the previous run.
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Name	Previous	Current	Ratio	Verdict
ProcessDocuments-4	03b2ca	1bb1cf
	346.00 B/op	28585.00 B/op	82.62	🔴

[github-actions]

🔴 Performance Degradation

Some benchmarks have degraded compared to the previous run.
Click on Show table button to see full list of degraded benchmarks.

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Name	Previous	Current	Ratio	Verdict
ProcessDocuments-4	03b2ca	707cf6
	346.00 B/op	28307.00 B/op	81.81	🔴