Doesn't look like FD is the problem. It shows -1 in /_nodes/stats/process. I think it means unlimited on Windows as per this post.
{
"cluster_name": "elasticsearch",
"nodes": {
"FPJhPMnZQ8qy70QkczcUUA": {
"timestamp": 1474685156386,
"name": "James Dr. Power",
"transport_address": "127.0.0.1:9300",
"host": "127.0.0.1",
"ip": [
"127.0.0.1:9300",
"NONE"
],
"process": {
"timestamp": 1474685156386,
"open_file_descriptors": -1,
"max_file_descriptors": -1,
"cpu": {
"percent": 11,
"total_in_millis": 32136
},
"mem": {
"total_virtual_in_bytes": 2369433600
}
}
}
}
}