We have over 9000 entries in timeline server web ui (see attachment), and actually reached default threshold. Regarding official documentation, in order to increase this number, we have to specify custom value for configuration property yarn.timeline-service.generic-application-history.max-applications. I've done so in Ambari's "Custom yarn-site" section, and set it to 20000. But problem is still there. I also checked yarn-site.xml if this property exists in it. And, of course, after configuration change, all affected services were restarted.
Would appreciate any help.