test: add kubernetes test on connection pool behaviour

[alaeddine-13]

closes: #4147

[codecov]

Codecov Report

Merging #4196 (ba9efc8) into master (def0a12) will increase coverage by 0.50%.
The diff coverage is 79.37%.

@@            Coverage Diff             @@
##           master    #4196      +/-   ##
==========================================
+ Coverage   86.53%   87.03%   +0.50%     
==========================================
  Files         118      114       -4     
  Lines        8338     8302      -36     
==========================================
+ Hits         7215     7226      +11     
+ Misses       1123     1076      -47     

Flag	Coverage Δ
daemon	42.50% <53.14%> (+0.39%)	⬆️
jina	86.78% <79.37%> (+1.10%)	⬆️

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

Impacted Files	Coverage Δ
jina/__init__.py	70.58% <ø> (ø)
jina/jaml/parsers/base.py	60.00% <0.00%> (ø)
jina/jaml/parsers/default/v1.py	0.00% <0.00%> (-76.20%)	⬇️
jina/types/request/__init__.py	100.00% <ø> (ø)
jina/proto/jina_pb2.py	58.10% <3.33%> (ø)
jina/clients/mixin.py	90.47% <25.00%> (ø)
jina/parsers/helper.py	45.18% <50.00%> (-0.34%)	⬇️
jina/clients/base/helper.py	85.48% <60.00%> (-0.24%)	⬇️
jina/clients/request/__init__.py	73.91% <66.66%> (ø)
jina/types/mixin.py	70.83% <66.66%> (-8.34%)	⬇️
... and 144 more

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[github-actions]

Latency summary

Current PR yields:

• 🐢🐢 index QPS at 872, delta to last 2 avg.: -36%
• 🐎🐎🐎🐎 query QPS at 45, delta to last 2 avg.: +65%
• 🐎🐎🐎🐎 avg flow time within 1.7432 seconds, delta to last 2 avg.: +15%
• 😶 import jina within 0.4023 seconds, delta to last 2 avg.: +1%

Breakdown

Version	Index QPS	Query QPS	Avg Flow Time (s)	Import Time (s)
current	872	45	1.7432	0.4023
2.6.4	1443	28	1.4989	0.3796
2.6.3	1320	25	1.5141	0.4147

Backed by latency-tracking. Further commits will update this comment.