I am trying to get all unique values in a given field using the following terms aggregations and it is returning a "can't communicate with server error" but I no that is not the actual issue because if I drop the size value to 2000000 it works:

 "size": 0,
       "terms": { "field": "name",
           "size": 4000000
} > myResults.txt

I am using Elastic Cloud with 16GB of RAM and 384GB of disk space and I believe the cluster just can't handle the larger number of results. Is there anyway to get all 4 million unique values out that I need for post processing? Any help that anyone could provide would be appreciated. Thanks.