Revert "Revert "[Upgrade Assistant] Refactor telemetry (#112177)" (#113665)"

[cjcenizal]

This reverts commit c385d49 (#113665) and fixes the bug described in that PR. Reimplements #112177.

How to review

The first commit is a mirror of the changes introduced in #112177, except for a couple minor divergences due to merge conflicts. You could probably pull up the diff from this PR side-by-side with that diff and just compare red/green patterns to ensure the code looks good.

The second and third commits are very small and should be straightforward to review.

Steps to test

Because this change is a reimplementation of #112177, the steps to test are the same as that one, with a couple additions:

• Create a 6.8 sample data set that contains ui_open attributes in the UA telemetry saved object by visiting Upgrade Assistant and navigating to the different tabs. Verify the saved object has this attribute by going to Advanced Settings, filtering down to "Telemetry" and clicking the "See an example of what we collect". A flyout will open. Search the JSON in the flyout for upgrade-assistant-telemetry and verify that some of the ui_open attributes have non-zero values.
• Start up ES using this data. Assuming your data is located atkibana/.es/6.8-data, this would be by running yarn es snapshot -E path.data=../6.8-data.
• Verify telemetry works by performing the testing steps described in [Upgrade Assistant] Refactor telemetry #112177.
• As you do so, verify that Kibana starts normally without crashing. This indicates that the saved object migration I implemented to fix the bug reported in Revert "[Upgrade Assistant] Refactor telemetry (#112177)" #113665 is working as expected.

[elasticmachine]

Pinging @elastic/kibana-stack-management (Team:Stack Management)

[yuliacech]

Hi @cjcenizal, thank you for fixing the migration bug! I tested the code locally and Kibana started without any errors. To test actual telemetry counters, I used "Advanced setting" and clicked the "See examples of the cluster data" link there. The data is collected correctly, though I noticed that we can't track right click on our links. But I think it's a limitation how events are handled on the buttons.

[TinaHeiligers]

We might be able to simplify the migration to removing the top level ui_open and ui_reindex fields but this works.

We might want to wrap the try/catch with a conditional based on finding entries in the blocklist to skip the transformation for docs that don't have the fields. (example: https://github.com/elastic/kibana/blob/master/src/plugins/visualizations/server/migrations/visualization_saved_object_migrations.ts#L143-L172)

For now, this works though.

[TinaHeiligers]

nit: I think we should probably wrap this in a conditional so that we don't end up running every doc through this migration.

[cjcenizal]

@elasticmachine merge upstream

[lukeelmers]

nit: IIRC omit already returns a new object, so the spread is unnecessary here

Suggested change

	attributes: {
	...omit(doc.attributes, attributesBlocklist),
	},
	attributes: omit(doc.attributes, attributesBlocklist),

[lukeelmers]

I don't think you need to use a try/catch to swallow errors here. The only operation you are performing is a call to omit, and if something goes wrong with that, it probably means you have a badly corrupted object that you probably want to know about instead of silently proceeding with the migration.

(Edit: Unless you are intentionally trying to hide this object from users because it is telemetry-related?)

[cjcenizal]

Good point, it's probably unnecessary. Hiding the object from users never occurred to me, but I don't think it's important to hide telemetry SOs from users.

[kibanamachine]

💚 Build Succeeded

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Metrics [docs]

Module Count

Fewer modules leads to a faster build time

id	before	after	diff
upgradeAssistant	144	145	+1

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
upgradeAssistant	135.9KB	136.4KB	+462.0B

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
upgradeAssistant	17.1KB	18.3KB	+1.2KB

Saved Objects .kibana field count

Every field in each saved object type adds overhead to Elasticsearch. Kibana needs to keep the total field count below Elasticsearch's default limit of 1000 fields. Only specify field mappings for the fields you wish to search on or query. See https://www.elastic.co/guide/en/kibana/master/development-plugin-saved-objects.html#_mappings

id	before	after	diff
upgrade-assistant-telemetry	13	4	-9

History

• 💚 Build #162259 succeeded b405eec
• 💔 Build #162175 failed dd06959

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