Reproduced this consistently a few times in AWS: config: 3 member replicaSet 2 delayed secondaries (set 3600) m3.medium version 3.2.1 steps (done via mongo shell): 1. enableMajorityReadConcern 2. insert something 3. query inserted document on primary using "local" readConcern as a sanity check 4. query inserted documented with readConcern majority expected results: the query should hang for a very long time (at least it happen to me after recreating this environment multiple times in AWS via CloudManager) Additional observations: The query hanged indefinitely for me when delay was 3600s. I was able to get the query to complete on 3.2.0 with delay set to 60s. The first query hanged for ~30s and returned no results as expected. Subsequent queries (on updates performed on the document) with this different configuration after the first returned without observed delay.