Disable bfetch in serverless

[lukasolson]

Summary

Part of #181938.

Disables bfetch in serverless by overriding the bfetch:disable advanced setting in the serverless.yml.

Bfetch was introduced to bypass the browser connection limit when multiple search requests are made. Here's a picture of what the network tab looks like with bfetch turned off in http1:

As the number of requests reaches the connection limit (6 on most modern browsers), requests stall until a connection is available.

In Cloud/serverless, we have a http2 proxy. Http2 does not have this browser connection limit. Turning off bfetch allows us to collect metrics to decide if we want to remove it altogether:

Bfetch enabled	Bfetch disabled (this PR)

In my tests, the overall time for a sample dashboard to load was actually smaller with bfetch disabled on http2 vs. bfetch enabled.

Checklist

• Documentation was added for features that require explanation or tutorials
• Unit or functional tests were updated or added to match the most common scenarios

[lukasolson]

/ci

[lukasolson]

/ci

[elasticmachine]

Pinging @elastic/kibana-data-discovery (Team:DataDiscovery)

[mattkime]

Code looks good and work well!

[pgayvallet]

Just FMI, could you tell me why we're doing it?

[lukasolson]

Just FMI, could you tell me why we're doing it?

I forgot to link to the issue, but there's more context here: #181938

[afharo]

@lukasolson, have you considered using the labels ci:project-deploy-* to test them on the actual serverless architecture before merging?

[thomasneirynck]

Can we double check the response is actually gzip encoded, or if it is the raw json? Just glanced at it, and wasn't 100% clear to me.

[lukasolson]

Can we double check the response is actually gzip encoded, or if it is the raw json? Just glanced at it, and wasn't 100% clear to me.

Spun up serverless locally to check, and it looks like it is gzip encoded:

[afharo]

Tested and LGTM

[kibana-ci]

💚 Build Succeeded

• Buildkite Build
• Commit: a3457d4
• Kibana Serverless Image: docker.elastic.co/kibana-ci/kibana-serverless:pr-183096-a3457d4b1fab
• Security Deployment
• Elasticsearch Serverless Deployment
• Observability Deployment

Metrics [docs]

Canvas Sharable Runtime

The Canvas "shareable runtime" is an bundle produced to enable running Canvas workpads outside of Kibana. This bundle is included in third-party webpages that embed canvas and therefor should be as slim as possible.

id	before	after	diff
module count	-	5414	+5414
total size	-	8.8MB	+8.8MB

History

• 💛 Build #212543 was flaky 4607099
• 💚 Build #211080 succeeded bbce7d6
• 💚 Build #210314 succeeded 2bec2c9
• 💚 Build #209992 succeeded b854c5c

To update your PR or re-run it, just comment with:
@elasticmachine merge upstream

cc @lukasolson