Slow Kibana after update 7.4.2 -> 7.9.2

Loading a dashboard with 5 visualizations takes 4x time with K7.9 than K7.4 (with exactly same indices and resources).

ES cluster has 3 nodes, all queries take no more than 1 seconde, but dashboard is loading on 10 secondes with Kibana 7.9.

By inspecting AJAX queries, I see K7.4 is using "msearch", whereas K7.9 is using async search. And in async search response, I see "took: 15000ms" !!! Thats really too much.

Is it normal ? Can I rollback to "msearch" strategy ?

Hello Thomas,

I think that the async search is not the problem itself: I found here that the async search is called if the search takes longer than 10 seconds. So, would the call be completed in 1 second the async search would not have been called.

Do you still have the old stack as a backup? Maybe it would help to compare the Explain plans of both versions?

Best regards
Wolfram

Thanks you,

ES query is fine:

  • I use exactly same data, same mapping, same CPU/RAM resources between ES7.4 and ES7.9 cluster
  • Exactly the same Kibana dashboard / vizu, with same ES queries
  • When I run the ES query in dev console, it takes less than 1 secondes

Async search is used all the time, here a screenshot of all AJAX calls by K7.9:

The last AJAX query gives: took: 24558 !!! where as the ES query it-self takes less 1 seconde. The query is just a date-histogram with sub terms aggregation, against 10G data.

To compare, here a screenshot of K7.4, same dashboard:

wait time is now 100ms ! according the last commits:

I understand now why I see hundred of AJAX calls ....