Nhat Nguyen 3a487379c3 Tighten no pending scheduled refresh check (#45025)
Previously, we use ThreadPoolStats to ensure that the scheduledRefresh
triggered by the internal refresh setting update is executed before we
index a new document. With that change (#40387), this test did not fail for 
the last 3 months. However, using ThreadPoolStats is not entirely watertight
as both "active" and "queue" count can be 0 in a very small interval
when ThreadPoolExecutor pulls a task from the queue but before marking
the corresponding worker as active (i.e., lock it).

Closes #39565
2019-08-01 09:06:22 -04:00
..