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
indexRequest.setPipeline(defaultPipeline);
                }
                if (IndexSettings.FINAL_PIPELINE.exists(indexSettings)) {
                    
                    finalPipeline = IndexSettings.FINAL_PIPELINE.get(indexSettings);
                    indexRequest.setFinalPipeline(finalPipeline);
                }
            } else if (indexRequest.index() != null) {
                
                
                
                String v2Template = MetadataIndexTemplateService.findV2Template(metadata, indexRequest.index(), false);
                if (v2Template != null) {
                    Settings settings = MetadataIndexTemplateService.resolveSettings(metadata, v2Template);
                    if (IndexSettings.DEFAULT_PIPELINE.exists(settings)) {
                        defaultPipeline = IndexSettings.DEFAULT_PIPELINE.get(settings);
                        
                    }
                    if (IndexSettings.FINAL_PIPELINE.exists(settings)) {
                        finalPipeline = IndexSettings.FINAL_PIPELINE.get(settings);
                        
                    }
                    indexRequest.setPipeline(Objects.requireNonNullElse(defaultPipeline, NOOP_PIPELINE_NAME));
                    indexRequest.setFinalPipeline(Objects.requireNonNullElse(finalPipeline, NOOP_PIPELINE_NAME));
                } else {
                    List<IndexTemplateMetadata> templates = MetadataIndexTemplateService.findV1Templates(
                        metadata,
                        indexRequest.index(),
                        null
                    );