To speed up recovery from a down time or restore from snapshot, use the following settings:
curl -XPUT -H 'Content-Type: application/json' 'http://localhost:9200/_cluster/settings' -d'
{
"persistent": {
"indices.recovery.max_bytes_per_sec": "1000mb",
"cluster.routing.allocation.node_concurrent_recoveries": "10"
}
}'