Lens editor gets into infinite search loop when searches take a while to complete and relative time range is used

[lizozom]

Kibana version:
7.16.1

Describe the bug:
I created a visualization containing a scripted field (not a runtime field).
Loading it for last 15 minutes sends kibana into an endless bsearch loop and it never finishes to load (I waited for over 3 minutes).

Steps to reproduce:

1. Go to this visualization
2. It never finishes to load properly

Expected behavior:
Visualization should either load or terminate \ show an error.

Screenshots (if relevant):

Errors in browser console (if relevant):

Provide logs and/or server output (if relevant):

Any additional context:

[elasticmachine]

Pinging @elastic/kibana-app-services (Team:AppServicesSv)

[flash1293]

Looks like a duplicate of #123030 , I already investigated the problem there. Waiting for input from @ppisljar and @dokmic

Edit: Oh wait, it's related to scripted fields, probably a separate issue, my bad.

[lizozom]

@flash1293 I think both problems are happening simultaneously there

[Dosant]

@flash1293, could it be that Lens editor re-runs the search in case the previous search took a long time to load (~1 minute)?

Maybe this code is executed when we got search results that took a while to load and lens triggers refetch?

kibana/x-pack/plugins/lens/public/state_management/context_middleware/index.ts

Lines 64 to 71 in d862d9b

	if (nowDiff > Math.max(timeRangeLength * TIME_LAG_PERCENTAGE_LIMIT, TIME_LAG_MIN_LIMIT)) {
	dispatch(
	setState({
	searchSessionId: data.search.session.start(),
	resolvedDateRange: getResolvedDateRange(timefilter),
	})
	);
	}

[flash1293]

@Dosant good find - @lizozom can you reproduce this issue with absolute time ranges as well (no usage of “now”)?

[Dosant]

@flash1293, absolute time range works. The search takes quite a while to complete.
But compared to the relative time range Lens doesn't trigger refetch when it completes so it doesn't gets stuck in the infinite loop the

[elasticmachine]

Pinging @elastic/kibana-vis-editors @elastic/kibana-vis-editors-external (Team:VisEditors)

[Dosant]

Maybe while fixing this, this would be a good opportunity for lens to add a shard_delay agg, so that it would be easier to test long-running searches in Lens editor. This would also help with functional test

#108201

[lizozom]

@flash1293 @Dosant I think I have another vis where it happens with an absolute timerange.
FYI

[Dosant]

@flash1293 @Dosant I think I have another vis where it happens with an absolute timerange. FYI

In this case, it doesn't look like you even got to the result? (no chart displayed)
So maybe it is just taking its time to complete in elasticsearch?

[lizozom]

Not sure, but the amount of requests seems to be growing larger with time.
It finished! You are correct. It's just incredibly slow

[flash1293]

I misunderstood the bug a bit - the chart is showing up, it's just kicking off a new search immediately as long as the editor is open. It's equivalent to not being able to turn off auto-refresh. This makes this bug way less severe as Lens is constantly sending out requests anyway in most usage scenarios. Changing the severity but still working on a fix.

While at it I will add the shard delay thing to make it easier to debug later on.