# Persistent queue and kafka output

**URL:** <https://discuss.elastic.co/t/persistent-queue-and-kafka-output/171120>\
**Category:** Logstash\
**Created:** [March 6, 2019, 1:19pm UTC](https://discuss.elastic.co/t/persistent-queue-and-kafka-output/171120 "2019-03-06T13:19:26Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![JohanRask](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/johanrask/32/22713_2.png) [@JohanRask](https://discuss.elastic.co/u/JohanRask)\
**Post date:** [March 6, 2019, 1:19pm UTC](https://discuss.elastic.co/t/persistent-queue-and-kafka-output/171120/1 "2019-03-06T13:19:26Z")

</div>

Hi,  
We are reading from kafka topics, performing different transformations and then write back to other kafka topics.

Since logstash does periodic commits to kafka we where not able to use inmemory queues and we are instead moving to persistent queues.

My question is when kafka output acknowledges a message, is it after a message has been successfully sent to kafka or only after it has been put in the producer buffer?

I would expect that it is ACK:ed after it has been successfully sent but I want to be certain.

Regards /Johan

---

<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [April 3, 2019, 1:24pm UTC](https://discuss.elastic.co/t/persistent-queue-and-kafka-output/171120/2 "2019-04-03T13:24:59Z")

</div>

This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.