[Breaking change] Removal of Timelion app

[stratoula]

Change description

Which release will ship the breaking change?

8.0

Describe the change. How will it manifest to users?
We are planning to remove the timelion app on v8.0 (not the visualization). On 7.9 we introduced the following notifications to the users to inform them about this change in order to be able to move their existing sheets on a dashboard.

• A warning on the timelion app (client-side) about the removal and a link to the documentation

• A warning on the server with the same message. The warning is being displayed only if the user has existing worksheets.

How many users will be affected?
The timelion sheets usage from our telemetry data for the last year is depicted here:

What can users do to address the change manually?

The documentation for the users can be found here

How could we make migration easier with the Upgrade Assistant?

We would love to notify the users also during the migration to v8.0. It is very possible that even with our warnings, both on server and client-side, the users will never see them. We want to identify if the users have created timelion worksheets and if yes to notify them that they are going to lose their sheets with the migration and a link with the steps that they should follow in order to not lose their graphs.

[elasticmachine]

Pinging @elastic/es-ui (Team:Elasticsearch UI)

[alisonelizabeth]

Hi @stratoula! Can you share how it can be detected if a user has any timelion worksheets?

[stratoula]

Hey @alisonelizabeth! The server code that does it can be found here https://github.com/elastic/kibana/blob/master/src/plugins/timelion/server/plugin.ts#L32. We use the savedObjectsClient and try to find the type timelion-sheet. If sheets are found then we display the deprecation message on the server

[alisonelizabeth]

Thanks @stratoula! Could you also include steps or link to documentation on the best way to set up Timelion sheets (for testing purposes)?

[stratoula]

Sure, Navigate to <kibana_url>/app/timelion, then click the Save button that is on the upper right menu. You will see two options:

• Save entire timelion sheet
• Save current expression

Click the first one, give a name and the sheet is ready!

[alisonelizabeth]

Hi @stratoula! Can this issue be closed now? This breaking change was registered via the new deprecations service in core in #94845.

It should display in Upgrade Assistant as follows (once #97159 is merged):

[stratoula]

@alisonelizabeth you are definitely right! I am closing it, thank you for taking care of it!