[Tarantool-patches] [PATCH v2 0/5] send feedback on start and on key events

[Vladislav Shpilevoy]

Thanks for the patchset, Sergey! Technically the patchset looks bearable.
Below text is for the people who forced us to do this ticket.


Disclaimer: this is not toxic. I mostly just ask questions and express
my opinion.

I don't like the patch. The hack to workaround some CI issues with a sleep,
and the behaviour we introduce on the whole. I don't think creation of a
first space/index makes any sense to track.

The reason about "going through a tutorial" is a very weak argument. Spaces
are created not only as a part of a tutorial obviously. And I see no other
reason for sending these "events".

This rant is for Mons, Artur, and whoever else pushed sending of that useless
information and introduction of a **known bug** which we hack with 10s sleep. I
bet they have no idea how to really use it **exactly**, not in some abstract
way they will try to figure out later, and they just wanted to send "something"
to close some story-points.

We on purpose **push buggy code** only to send these feedback events we don't
know what to do with.

Here is what I see in the issue:

	In order for us to assess the real situation for the product, it is
	necessary to send feedback from the product immediately after the
	launch and after the key actions are completed.

How the hell is it related to a "real situation for the product"? How is it
"necessary"? What was wrong with the feedback we have now? How are the
instances working less than 1 hour are so important? And why do you need to
know exactly when a first space/index was created? Well, even if we need it,
we could remember the timestamps and send them with the next regular report.

Another cite:

	If Tarantool was installed using a script from the Download page,
	then you need to send feedback immediately and further after the
	following events are completed:

	...

	The rest of Tarantool that were downloaded outside of the Download
	page does not contain a special meta-file and should be considered as
	internal usage and no feedback sent from them. These are usually CI
	instances.

What is that "metafile"? We send the feedback anyway regardless of some metafile
in this patch, and from where the executable file was downloaded. Which again
renders this "feature" absolutely useless. Besides, creation of a first index
and space won't cover instances which don't create any indexes and spaces. For
example, vshard routers.

Additionally, implementation of this code stole time from the scaling team on
writing the code, doing the reviews, doing the review fixes. How is it even
related to the scaling team at all? Why was it so urgent and more important than
finishing a fix for a serious bug in the synchronous replication? I would propose
Artur to send a PR for that next time. Tickets like that should go to the
wishlist right away, instead of the known crashes and optimizations.

I hope we will drop these feedback events in the future when will realize it
does not help anyhow with a problem which can't even be properly formulated,
and because it introduces a bug we don't know for sure why is happening, and
how can be fixed except the 10s sleep hack.