Implement single connection benchmark

[sylwiaszunejko]

API for hooking to Write() and Read() of Conn struct added. New struct TrafficRecorder added for enabling recording and mocking single Connection flow.

Fixes: #296

[sylwiaszunejko]

Adding this as a draft, because I wanted to make sure this part looks like intended in the issue, before pushing the rest.

[sylwiaszunejko]

@dkropachev could you take a look?

[sylwiaszunejko]

@dkropachev I pushed some changes, it is clearly wip, but I want to make sure the direction is right

[sylwiaszunejko]

@dkropachev I pushed some changes, it is still not a complete solution, I am not sure how to replay the traffic properly, but it is in such a state that it should be possible to state if the direction is good

[dkropachev]

Probably you could reuse something from TestServer from conn_test.go to replay traffic

[dkropachev]

@sylwiaszunejko , we need to disable these guys for NewSingleHostQueryExecutor

		s.hostSource = &ringDescriber{session: s}
		s.ringRefresher = newRefreshDebouncer(ringRefreshDebounceTime, func() error { return refreshRing(s.hostSource) })

[dkropachev]

Final change I it is finally ready, great job, it produces pretty stable results:

cpu: 12th Gen Intel(R) Core(TM) i9-12900HK
BenchmarkSingleConnectionInsert
BenchmarkSingleConnectionInsert/Insert
BenchmarkSingleConnectionInsert/Insert/Case0
BenchmarkSingleConnectionInsert/Insert/Case0-20           242354              4332 ns/op
BenchmarkSingleConnectionInsert/Insert/Case1
BenchmarkSingleConnectionInsert/Insert/Case1-20           295485              4334 ns/op
BenchmarkSingleConnectionInsert/Insert/Case2
BenchmarkSingleConnectionInsert/Insert/Case2-20           304800              4332 ns/op
BenchmarkSingleConnectionInsert/Insert/Case3
BenchmarkSingleConnectionInsert/Insert/Case3-20           266346              4240 ns/op
BenchmarkSingleConnectionInsert/Insert/Case4
BenchmarkSingleConnectionInsert/Insert/Case4-20           254448              4042 ns/op
BenchmarkSingleConnectionInsert/Insert/Case5
BenchmarkSingleConnectionInsert/Insert/Case5-20           288975              4270 ns/op
BenchmarkSingleConnectionInsert/Insert/Case6
BenchmarkSingleConnectionInsert/Insert/Case6-20           279169              4152 ns/op
BenchmarkSingleConnectionInsert/Insert/Case7
BenchmarkSingleConnectionInsert/Insert/Case7-20           294770              4074 ns/op
BenchmarkSingleConnectionInsert/Insert/Case8
BenchmarkSingleConnectionInsert/Insert/Case8-20           299186              3994 ns/op
BenchmarkSingleConnectionInsert/Insert/Case9
BenchmarkSingleConnectionInsert/Insert/Case9-20           305224              4147 ns/op
PASS

[dkropachev]

@sylwiaszunejko , I spot another problem, standard benchrmark library does not collect goroutine stats, which means that some parts are not shown in results.
Unfortunately due to the library limitations, there is only one way to fix it is to come up with custom test library, which is a bit cumbersome.
Given all that I think it is better to merge it and look for solution that would show everything later, WDYT?

[sylwiaszunejko]

@sylwiaszunejko , I spot another problem, standard benchrmark library does not collect goroutine stats, which means that some parts are not shown in results. Unfortunately due to the library limitations, there is only one way to fix it is to come up with custom test library, which is a bit cumbersome. Given all that I think it is better to merge it and look for solution that would show everything later, WDYT?

I agree

[sylwiaszunejko]

I created an issue to collect goroutine stats #330