[DOCS] How to upgrade a Fleet Server on premise and best practices

[lucabelluccini]

How to upgrade Fleet Server on premise and best practices to avoid downtime.
Might include:

• Using more than 1 Fleet Server
• How to load balance multiple Fleet Servers
• Upgrade order and if it supports rolling upgrades or not

Improved guidance for air-gapped environments.

[karenzone]

Is there a way to see who set the project fields for this (and other) issues?

"Estimate," for example. With the limited details and scope available, no SME identified, and no input from writers, <2 days seems overly optimistic.

[dedemorton]

With the limited details and scope available, no SME identified, and no input from writers, <2 days seems overly optimistic.

Agreed. AFAIK, we don't have any primary source materials to work from. If we are expecting a writer to learn how to install and upgrade Fleet Server on prem and document best practices (along with load balancing and air gapped environments), this effort is going to take more than a week.

@karenzone I've added the needs-input label though I'm not sure if your team is tracking that label these days.

[lucabelluccini]

This should also be integrated with the wider Stack docs https://www.elastic.co/guide/en/elastic-stack/7.17/upgrading-elastic-stack.html as we document upgrading Elastic Agent but not when to upgrade Fleet Server.

[nimarezainia]

Agreed this is not a docs issue, I had placed it on our backlog as we need engineering assigned to help with the details. (fyi @pierrehilbert )

@lucabelluccini for your reference new air-gap docs are now here: https://www.elastic.co/guide/en/elastic-stack/current/air-gapped-install.html

[nimarezainia]

@lucabelluccini, coming back to this. Considerable amount of effort went into defining how to install and order of upgrade in the air-gap environments: https://www.elastic.co/guide/en/fleet/8.x/air-gapped.html

In context of overall stack installation and upgrade in an air-gap/on-premise environments we also created this document: https://www.elastic.co/guide/en/elastic-stack/current/air-gapped-install.html#air-gapped-fleet which essentially says that Fleet Server is just another agent.

@kilfoyle perhaps we could write a paragraph to address the first few bullets in the description. I'm not sure this warrants engineering time and I can write it up. I feel like majority of the content is in the docs but perhaps not in one place. May be we can add a section here to cover these questions. wdyt?

[kilfoyle]

@nimarezainia Certainly. I can add in a paragraph and I like the location. If either you or @lucabelluccini can provide just a few bullet points with what the advice/recommendations should be, I can add it in. Thanks!