Failed today: http://build-us-00.elastic.co/job/es_core_master_centos/8366/
Doesn't reproduce here locally.

Also this failed before recently:
http://build-us-00.elastic.co/job/es_core_master_centos/8341/ (2 nov)
http://build-us-00.elastic.co/job/es_core_master_centos/8306/ (1 nov)

Before that I can't find any failures for this test, so maybe this failure has been introduced recently?