# Grokparsefailure output error

**URL:** <https://discuss.elastic.co/t/grokparsefailure-output-error/209350>\
**Category:** Logstash\
**Created:** [November 25, 2019, 5:09pm UTC](https://discuss.elastic.co/t/grokparsefailure-output-error/209350 "2019-11-25T17:09:06Z")\
**Posts on this page:** 1\
**Showing post:** 8

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**Author:** ![Badger](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/badger/32/25190_2.png) [@Badger](https://discuss.elastic.co/u/Badger)\
**Post date:** [December 6, 2019, 8:17pm UTC](https://discuss.elastic.co/t/grokparsefailure-output-error/209350/8 "2019-12-06T20:17:51Z")

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Use log.level trace. filewatch will indicate what length it thinks the file is, how much of it it has read, when it flushes events to the pipeline etc. You should see a bunch of messages like [these](https://discuss.elastic.co/t/when-logstash-shutdown-renam-file-and-data-can-be-lost-or-duplicated/192669/3).

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