# Error: Cannot use more than 1 filter worker
**URL:** https://discuss.elastic.co/t/error-cannot-use-more-than-1-filter-worker/782
**Category:** Logstash
**Created:** [May 16, 2015, 6:38am UTC](https://discuss.elastic.co/t/error-cannot-use-more-than-1-filter-worker/782 "2015-05-16T06:38:55Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@allenmchan](https://discuss.elastic.co/u/allenmchan)
#### Post date: [May 16, 2015, 6:38am UTC](https://discuss.elastic.co/t/error-cannot-use-more-than-1-filter-worker/782/1 "2015-05-16T06:38:55Z")
Has anyone seen this error before? First time i saw it on 1.5 GA
"Error: Cannot use more than 1 filter worker because the following plugins don't work with more than one worker: multiline, multiline, multiline"
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### Author:  [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)
#### Post date: [May 16, 2015, 7:16am UTC](https://discuss.elastic.co/t/error-cannot-use-more-than-1-filter-worker/782/2 "2015-05-16T07:16:30Z")
When you are using the multiline filter, it needs to process all log lines in sequence in order to be able to assemble them correctly, which is why it will give incorrect results if more than one worker is used as these will process lines in parallel. If you however instead assemble multilines already within the input plugin using the [multiline codec] ([https://www.elastic.co/guide/en/logstash/current/plugins-codecs-multiline.html](https://www.elastic.co/guide/en/logstash/current/plugins-codecs-multiline.html)), you will be free to use multiple workers.
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### Author:  [@allenmchan](https://discuss.elastic.co/u/allenmchan)
#### Post date: [May 18, 2015, 2:28am UTC](https://discuss.elastic.co/t/error-cannot-use-more-than-1-filter-worker/782/3 "2015-05-18T02:28:17Z")
Thank you Christian. I just wish that the 1.5 ChangeLog would be more explicit about the force of moving from multiline filter to multiline codec. Not a big deal i guess
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 6, 2017, 5:39am UTC](https://discuss.elastic.co/t/error-cannot-use-more-than-1-filter-worker/782/4 "2017-07-06T05:39:46Z")