What are Kibana Index and Kibana Task Manager?

I've been playing around with the new Kibana and Elasticsearch 7. I spun each up and noticed that kibana added two new indices, .kibana_1 and .kibana_task_manager_1. What has happened to the old .kibana index, and I can't seem to find documentation regarding these new indices online.

Could someone redirect me to documentation that covers this information in detail?

the .kibana index has been transformed to .kibana_x (there is also a .kibana alias that points at the latest .kibana_x index) which is used to maintain backup when upgrading/migrating. For example if your .kibana_1 index is your main index and then you upgrade your Kibana instalation, Kibana will copy that index into .kibana_2, perform the migrations and then change the .kibana alias to point to .kibana_2.

Thanks for the reply, by chance is there also documentation that reference this change?
Also what is the kibana_task_manager index?

https://www.elastic.co/guide/en/kibana/6.7/upgrade-migrations.html
This is pretty much the documentation outside of the details you can find in the PRs that merged it.

as for the task_manager index it's pretty much what the name says. It manages the running taks that can happen in Kibana, like monitoring, reporting and so on.
You can read more about it in the initial issue: https://github.com/elastic/kibana/issues/23632 and the related ones.

Thanks, much appreciated.