# Using ingestion pipeline to add metadata information to documents
**URL:** https://discuss.elastic.co/t/using-ingestion-pipeline-to-add-metadata-information-to-documents/74907
**Category:** Elasticsearch
**Created:** [February 13, 2017, 4:57pm UTC](https://discuss.elastic.co/t/using-ingestion-pipeline-to-add-metadata-information-to-documents/74907 "2017-02-13T16:57:58Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@nidheeshb](https://discuss.elastic.co/u/nidheeshb)
#### Post date: [February 13, 2017, 4:57pm UTC](https://discuss.elastic.co/t/using-ingestion-pipeline-to-add-metadata-information-to-documents/74907/1 "2017-02-13T16:57:59Z")
I am trying to use an Ingestion pipeline to add \_timestamp field to the documents.
While using the ingestion simulate API , the response contains the \_timestamp field that gets added due to the pipeline processor
```
POST _ingest/pipeline/_simulate?verbose
{
"pipeline": {
"description": "Adds a timestamp field at the current time",
"processors": [
{
"set": {
"field": "_timestamp",
"value": "{{_ingest.timestamp}}"
}
}
]
},
"docs":[
{
"_index":"newindex",
"_type": "document",
"_id":"1",
"_source":{
"example":"data3"
}
}
]
}
```
But after issuing a write request using the pipeline, the **\_timestamp** field fails to get added to the document source. Changing the field name from \_timestamp to timestamp seems to work though.
---
### Author:  [@msimos](https://discuss.elastic.co/u/msimos)
#### Post date: [February 13, 2017, 7:59pm UTC](https://discuss.elastic.co/t/using-ingestion-pipeline-to-add-metadata-information-to-documents/74907/2 "2017-02-13T19:59:19Z")
\_timestamp was removed in 5.x:
[https://www.elastic.co/guide/en/elasticsearch/reference/current/breaking\_50\_mapping\_changes.html#\_literal\_\_timestamp\_literal\_and\_literal\_\_ttl\_literal](https://www.elastic.co/guide/en/elasticsearch/reference/current/breaking_50_mapping_changes.html#_literal __timestamp_literal_and_literal__ ttl_literal)
Also it appears that \_timestamp is still a reserved name. So this is why it works when you just use timestamp. You can see the error by adding a document with a field name called \_timestamp.
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [March 13, 2017, 8:00pm UTC](https://discuss.elastic.co/t/using-ingestion-pipeline-to-add-metadata-information-to-documents/74907/3 "2017-03-13T20:00:24Z")
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