# Trapping mapper\_parsing\_exception original messages
**URL:** https://discuss.elastic.co/t/trapping-mapper-parsing-exception-original-messages/176975
**Category:** Logstash
**Created:** [April 15, 2019, 9:17pm UTC](https://discuss.elastic.co/t/trapping-mapper-parsing-exception-original-messages/176975 "2019-04-15T21:17:09Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@jeffkirk1](https://discuss.elastic.co/u/jeffkirk1)
#### Post date: [April 15, 2019, 9:17pm UTC](https://discuss.elastic.co/t/trapping-mapper-parsing-exception-original-messages/176975/1 "2019-04-15T21:17:09Z")
Hi there. I am debugging a Logstash filter pipeline that occasionally throws an Elasticsearch indexing error.
Long story short is that I am trying to parse a log message from an application into key-value pairs using a Ruby filter. Sometimes the log message is broken into key/value pairs incorrectly, and a string value is returned for a field that should be a Long.
I don't need to go into too much detail; I'm just looking for a way to make Logstash trap the mapper\_parsing\_exception and save the original event data to another index or to a Kafka topic or a file... really, to anything that lets me examine the original event and try to work backward to find my bug.
Is there such a mechanism in Logstash? I'm currently using version 6.7.1.
Thanks!
Jeff Kirk
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### Author:  [@Badger](https://discuss.elastic.co/u/Badger)
#### Post date: [April 15, 2019, 9:22pm UTC](https://discuss.elastic.co/t/trapping-mapper-parsing-exception-original-messages/176975/2 "2019-04-15T21:22:15Z")
Are you aware of [dead letter queues](https://www.elastic.co/guide/en/logstash/current/dead-letter-queues.html)?
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### Author:  [@jeffkirk1](https://discuss.elastic.co/u/jeffkirk1)
#### Post date: [April 16, 2019, 12:25am UTC](https://discuss.elastic.co/t/trapping-mapper-parsing-exception-original-messages/176975/3 "2019-04-16T00:25:14Z")
Hi Badger,
That looks perfect! Have never used that feature up to now. Thanks!
Jeff
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [May 14, 2019, 12:25am UTC](https://discuss.elastic.co/t/trapping-mapper-parsing-exception-original-messages/176975/4 "2019-05-14T00:25:17Z")
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