We use `totalMetrics` with a `startTimeInNanos` and a call to `postIngest` to track the 'total time' that ingest is running for a given document. You can imagine it's a little stopwatch that we start and stop. Unfortunately, I think we're stopping the stopwatch just a little too soon, on the start side, we include the time spent transforming the document into an `IngestDocument`, but we do not include the (non-negligible) time transforming from an `IngestDocument` after the pipeline logic has run.

That is, the call to `sourceAsMap` is included:

https://github.com/elastic/elasticsearch/blob/d03664f84f15dcfcb900cf2d43121ca9d89bdda8/server/src/main/java/org/elasticsearch/ingest/IngestService.java#L905

But the call to `source` is not:

https://github.com/elastic/elasticsearch/blob/d03664f84f15dcfcb900cf2d43121ca9d89bdda8/server/src/main/java/org/elasticsearch/ingest/IngestService.java#L948

The consequence of this is that the `total` ingest stats doesn't actually reflect the true time spent in ingest code:

```
GET _nodes/stats?filter_path=nodes.*.ingest
{
  "nodes" : {
    "Aysm6ztIRne2ES5ktyuqtw" : {
      "ingest" : {
        "total" : {
          "count" : 1,
          "time_in_millis" : 110, <--- this should be a little higher than it is
```
server/src/main/java/org/elasticsearch/ingest/IngestService.java
handler.accept(null);
                } else {
                    org.elasticsearch.script.Metadata metadata = ingestDocument.getMetadata();
                    
                    
                    indexRequest.index(metadata.getIndex());
                    indexRequest.id(metadata.getId());
                    indexRequest.routing(metadata.getRouting());
                    indexRequest.version(metadata.getVersion());
                    if (metadata.getVersionType() != null) {
                        indexRequest.versionType(VersionType.fromString(metadata.getVersionType()));
                    }
                    Number number;
                    if ((number = metadata.getIfSeqNo()) != null) {
                        indexRequest.setIfSeqNo(number.longValue());
                    }
                    if ((number = metadata.getIfPrimaryTerm()) != null) {
                        indexRequest.setIfPrimaryTerm(number.longValue());
                    }
                    try {
                        boolean ensureNoSelfReferences = ingestDocument.doNoSelfReferencesCheck();
                        indexRequest.source(ingestDocument.getSource(), indexRequest.getContentType(), ensureNoSelfReferences);
                    } catch (IllegalArgumentException ex) {
                        
                        
                        
                        
                        totalMetrics.ingestFailed();
                        handler.accept(
                            new IllegalArgumentException(