The ingest stats include the following statistics:
* `ingest.total.count`- The total number of document ingested during the lifetime of this node
* `ingest.total.time_in_millis` - The total time spent on ingest preprocessing documents during the lifetime of this node
* `ingest.total.current` - The total number of documents currently being ingested.
* `ingest.total.failed` - The total number ingest preprocessing operations failed during the lifetime of this node
Also these stats are returned on a per pipeline basis.
Internally the put pipeline API uses this information in node info API to validate if all specified processors in a pipeline exist on all nodes in the cluster.
Martijn van Groningen
Tal Levy
Clinton Gormley
DeDe Morton