# Logstash duplicate line / send log with elasticsearch:9200 no response **URL:** \ **Category:** Logstash\ **Created:** [March 28, 2016, 4:47pm UTC](https://discuss.elastic.co/t/logstash-duplicate-line-send-log-with-elasticsearch-9200-no-response/45612 "2016-03-28T16:47:28Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![pittoch](https://avatars.discourse-cdn.com/v4/letter/p/df788c/32.png) [@pittoch](https://discuss.elastic.co/u/pittoch)\ **Post date:** [March 28, 2016, 4:47pm UTC](https://discuss.elastic.co/t/logstash-duplicate-line-send-log-with-elasticsearch-9200-no-response/45612/1 "2016-03-28T16:47:28Z")
Hi, I use Logstash with CSV files sources. What happens if logstash can not contact ElasticSearch on 9200 port. They sent the logs will be reissued , or the logs are lost ? Dy ou know a concept of primary key to reject duplicates lines ? I find in another topic a system of hash [Logstash Duplicate message](https://discuss.elastic.co/t/logstash-duplicate-message/26096) Regards ---
**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\ **Post date:** [March 29, 2016, 9:01pm UTC](https://discuss.elastic.co/t/logstash-duplicate-line-send-log-with-elasticsearch-9200-no-response/45612/2 "2016-03-29T21:01:14Z")
> [@pittoch](#): > > They sent the logs will be reissued , or the logs are lost ? This should explain that part - [How Logstash Works | Logstash Reference [8.11] | Elastic](https://www.elastic.co/guide/en/logstash/current/pipeline.html) ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 5:04am UTC](https://discuss.elastic.co/t/logstash-duplicate-line-send-log-with-elasticsearch-9200-no-response/45612/3 "2017-07-06T05:04:52Z")