# Logstash Grok Filter breaks Single log line as 2 lines

**URL:** <https://discuss.elastic.co/t/logstash-grok-filter-breaks-single-log-line-as-2-lines/102020>\
**Category:** Logstash\
**Created:** [September 27, 2017, 7:11pm UTC](https://discuss.elastic.co/t/logstash-grok-filter-breaks-single-log-line-as-2-lines/102020 "2017-09-27T19:11:07Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![vijay.sangha](https://avatars.discourse-cdn.com/v4/letter/v/4491bb/32.png) [@vijay.sangha](https://discuss.elastic.co/u/vijay.sangha)\
**Post date:** [September 27, 2017, 7:11pm UTC](https://discuss.elastic.co/t/logstash-grok-filter-breaks-single-log-line-as-2-lines/102020/1 "2017-09-27T19:11:07Z")

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I am working to write a simple grok pattern and I have generated a grok filter which works awsome in grok debugger but when I use it in logstash, it generates 2 lines out of single line of log. these message also not propagating to ES.

I am using Filebeat[5.3.0]--\>Logstash[5.3.0]--\>ElasticSearch[5.3.0]

**Log Line :-**

[WARN] 2017-08-29 16:42:24.771 [http-0.0.0.0:8042-3] PageNotFound - Request method 'POST' not supported

**Grok Filter :-**

[%{LOGLEVEL:LOG\_LEVEL}\] %{TIMESTAMP\_ISO8601:timestamp\_match} %{GREEDYDATA:message}

**Logstash processed message :-**

{  
"offset" =\> 9438,  
"timestamp\_match" =\> "2017-09-25 20:02:18.771",  
"input\_type" =\> "log",  
"source" =\> "/my/source/logfile.log",  
"message" =\> [  
**[0] "[WARN] 2017-09-25 20:02:18.771 [http-0.0.0.0:8042-2] PageNotFound - Request method 'POST' not supported",**  
**[1] " [http-0.0.0.0:8042-2] PageNotFound - Request method 'POST' not supported"**  
\*\* ],\*\*  
"type" =\> "log",  
"env" =\> "UAT",  
"tags" =\> [  
[0] "uat",  
[1] "beats\_input\_codec\_plain\_applied"  
],  
"log\_type" =\> "spring-logs",  
"component" =\> "App",  
"@timestamp" =\> 2017-09-25T20:02:18.771Z,  
"@version" =\> "1",  
"beat" =\> {  
"version" =\> "5.3.0"  
},  
"host" =\> "mu-host",  
"LOG\_LEVEL" =\> "WARN"  
}

Does someone know why would this happen?

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<div class="post-metadata">

**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\
**Post date:** [September 27, 2017, 7:30pm UTC](https://discuss.elastic.co/t/logstash-grok-filter-breaks-single-log-line-as-2-lines/102020/2 "2017-09-27T19:30:29Z")

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I believe the reason is that you are capturing the final `GREEDYDATA` pattern into a field that already exists (`message`) without setting [overwrite](https://www.elastic.co/guide/en/logstash/5.6/plugins-filters-grok.html#plugins-filters-grok-overwrite) to `true`.

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<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:** [October 25, 2017, 7:31pm UTC](https://discuss.elastic.co/t/logstash-grok-filter-breaks-single-log-line-as-2-lines/102020/3 "2017-10-25T19:31:13Z")

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