# Explain Periodic\_flush in logsatsh common fields

**URL:** https://discuss.elastic.co/t/explain-periodic-flush-in-logsatsh-common-fields/247328
**Category:** Logstash
**Created:** [September 3, 2020, 5:41am UTC](https://discuss.elastic.co/t/explain-periodic-flush-in-logsatsh-common-fields/247328 "2020-09-03T05:41:16Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![SKumarMN](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/skumarmn/32/27537_2.png) [@SKumarMN](https://discuss.elastic.co/u/SKumarMN)
#### Post date: [September 3, 2020, 5:41am UTC](https://discuss.elastic.co/t/explain-periodic-flush-in-logsatsh-common-fields/247328/1 "2020-09-03T05:41:16Z")

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Hi,

Under Logstash common fields, I see a field names Periodic\_flush. Could you please explain whats is used for and also give an example with respect to translate plugin

[https://www.elastic.co/guide/en/logstash/current/plugins-filters-translate.html#plugins-filters-translate-periodic\_flush](https://www.elastic.co/guide/en/logstash/current/plugins-filters-translate.html#plugins-filters-translate-periodic_flush)

[https://www.elastic.co/guide/en/logstash/current/plugins-filters-http.html#plugins-filters-http-periodic\_flush](https://www.elastic.co/guide/en/logstash/current/plugins-filters-http.html#plugins-filters-http-periodic_flush)

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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: [September 3, 2020, 3:35pm UTC](https://discuss.elastic.co/t/explain-periodic-flush-in-logsatsh-common-fields/247328/2 "2020-09-03T15:35:29Z")

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periodic\_flush is a configuration item that filters inherit from the [base](https://github.com/elastic/logstash/blob/297a017ef7656bb698248a8d73150353779f0ef0/logstash-core/lib/logstash/filters/base.rb#L133) filter class. For a translate filter it has no use. For an aggregate filter it is used to trigger the flushing of events based on timeouts. Whenever the flush method is called (every 3 seconds?) the filter checks to see if any items in the map have expired.

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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: [October 1, 2020, 3:35pm UTC](https://discuss.elastic.co/t/explain-periodic-flush-in-logsatsh-common-fields/247328/3 "2020-10-01T15:35:41Z")

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