# How to re-analyze data that has already been ingested?

**URL:** https://discuss.elastic.co/t/how-to-re-analyze-data-that-has-already-been-ingested/245612
**Category:** Elasticsearch
**Created:** [August 19, 2020, 1:39pm UTC](https://discuss.elastic.co/t/how-to-re-analyze-data-that-has-already-been-ingested/245612 "2020-08-19T13:39:33Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![Stephan\_Stachurski](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/stephan_stachurski/32/74168_2.png) [@Stephan\_Stachurski](https://discuss.elastic.co/u/Stephan_Stachurski)
#### Post date: [August 19, 2020, 1:39pm UTC](https://discuss.elastic.co/t/how-to-re-analyze-data-that-has-already-been-ingested/245612/1 "2020-08-19T13:39:33Z")

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I was trying to figure out how to extract a field from a set of log messages, and most of the answers online suggest that you should handle this upstream, by using dissect on filebeat or something like that.

What do I do if I have a ton of log messages that have already been ingested without dissect, and I want to analyze them?

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### Author: ![flash1293](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/flash1293/32/41227_2.png) [@flash1293](https://discuss.elastic.co/u/flash1293)
#### Post date: [August 19, 2020, 1:44pm UTC](https://discuss.elastic.co/t/how-to-re-analyze-data-that-has-already-been-ingested/245612/2 "2020-08-19T13:44:02Z")

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This is not really a Kibana question, but you can define an ingest pipeline like shown here: [https://www.elastic.co/guide/en/elasticsearch/reference/master/ingest.html](https://www.elastic.co/guide/en/elasticsearch/reference/master/ingest.html)

For extracting a field you can use the grok processor for example: [https://www.elastic.co/guide/en/elasticsearch/reference/master/grok-processor.html](https://www.elastic.co/guide/en/elasticsearch/reference/master/grok-processor.html)

and then re-index your data through the pipeline: [https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-reindex.html](https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-reindex.html)

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### Author: ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)
#### Post date: [September 16, 2020, 1:44pm UTC](https://discuss.elastic.co/t/how-to-re-analyze-data-that-has-already-been-ingested/245612/3 "2020-09-16T13:44:08Z")

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