Kibana visualization edit mode is extreamly slow

[Sergey_Chernecov]

I use CCS-based index patterns to create dashboards and searches among ~50 projects.
Something like that: logs-*:logstash-*
Everything works as magic except...

Every action in visualization edit mode freezes Kibana UI. (without API calls, simple javascript processing)
I believe it is connected with having about 20K of fields in index pattern (not index itself)

From time to time it is not even possible to load visualization creation page based on this index pattern.
Question is - what should I do to make it work fast, like it is for smaller amount of fields.

P.S. Problem is definitely not in elasticsearch queries, because API calls are not being executed when it is so slow. May be connected with javascript processing big amount of data on each action, or passing state on each action, don't know..

Thanks in advance.

Kibana: 6.4.1!

Update 1: (trying to load simple discover page, not even visualization)

Update 2: (trying to load simple discover page, not even visualization)
Kibana 6.3.2 works faster and doesn't have this problem with javascript.

Update 3:
Looks like it is connected with "Source filters". (maybe not)
If I have a pattern that matches tons of fields, this problem occur even on 6.3.2

[tsullivan (Tim Sullivan)]

Having tons of fields is definitely the problem here. The information for all those fields comes into the browser in one shot and it's asking quite a lot for the browser to parse it all into Javascript objects. Parsing JSON is a CPU-intensive, I/O blocking operation for Javascript. The "idle" time you have highlighted seems like it would be the time spent waiting for parsing to finish, since anything else would be blocked during this time.

There's a long-standing issue, https://github.com/elastic/kibana/issues/1540 about this.

[Sergey_Chernecov]

Thank for the answer.
Thing is that something was definitely changed between 6.3.2 and 6.4.1 versions of Kibana.

Elastic is doing a great job with all products such as Elasticsearch, Logstash, Beats.. on the other hand Kibana quality seems like goes down and this scares me, because I really like whole Elastic stack, and using it since 0.92.

I actually don't really understand why to pass this whole JSON thing to frontend when it is possible to analyze and process everything on backend side as far as everything is stored in .kibana.

What can be next actions items on this topic, in your opinion?
How could I help the communication to focus on this problem?

Thanks.