MAPREDUCE-3811 introduced a separate config key for overriding the max retries applied to RPC connections from the MapReduce Client to the MapReduce Application Master. This was done to make failover from the AM to the MapReduce History Server faster in the event that the AM completes while the client thinks it's still running. However, the RPC client uses a separate setting for socket timeouts, and this one is not overridden. The default for this is 45 retries with a 20-second timeout on each retry. This means that in environments subject to connection timeout instead of connection refused, the client waits 15 minutes for failover.