# Drop logstash logs not containing certain field

**URL:** https://discuss.elastic.co/t/drop-logstash-logs-not-containing-certain-field/348626
**Category:** Logstash
**Created:** [December 5, 2023, 10:02am UTC](https://discuss.elastic.co/t/drop-logstash-logs-not-containing-certain-field/348626 "2023-12-05T10:02:37Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![e.vedelaar](https://avatars.discourse-cdn.com/v4/letter/e/bb73d2/32.png) [@e.vedelaar](https://discuss.elastic.co/u/e.vedelaar)
#### Post date: [December 5, 2023, 10:02am UTC](https://discuss.elastic.co/t/drop-logstash-logs-not-containing-certain-field/348626/1 "2023-12-05T10:02:37Z")

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I want to drop all logs who don't contain the dns.question.name field (or if the field is empty) how would i do this?

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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 5, 2023, 5:23pm UTC](https://discuss.elastic.co/t/drop-logstash-logs-not-containing-certain-field/348626/2 "2023-12-05T17:23:13Z")

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[This issue](https://github.com/elastic/logstash/issues/14422) against the (broken) [best-practice document](https://github.com/elastic/logstash/blob/main/docs/static/best-practice.asciidoc#check-to-see-if-a-boolean-field-exists) shows you how to test this in a way that works for all field types, including boolean.

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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: [January 2, 2024, 7:23pm UTC](https://discuss.elastic.co/t/drop-logstash-logs-not-containing-certain-field/348626/3 "2024-01-02T19:23:37Z")

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