elasticsearch/elasticsearch — pull request #6996 by s1monw (2014-07-23 20:02:36+00:00)
Title: Add `wait_if_ongoing` option to _flush requests

This commit adds the ability to force blocking on the flush operaition
to make sure all files have been written and synced to disk. Without
this option a flush might be executing at the same time causing the
current flush to fail and return before all files being synced.