# Get rid of duplicated items

**URL:** https://discuss.elastic.co/t/get-rid-of-duplicated-items/40630
**Category:** Logstash
**Created:** [February 1, 2016, 12:47pm UTC](https://discuss.elastic.co/t/get-rid-of-duplicated-items/40630 "2016-02-01T12:47:07Z")
**Posts on this page:** 5
**Page:** 1

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### Author: ![nkoleff](https://avatars.discourse-cdn.com/v4/letter/n/d9b06d/32.png) [@nkoleff](https://discuss.elastic.co/u/nkoleff)
#### Post date: [February 1, 2016, 12:47pm UTC](https://discuss.elastic.co/t/get-rid-of-duplicated-items/40630/1 "2016-02-01T12:47:07Z")

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Hello,

I've got some duplicated items in logstash which I want to get rid of in the future with implementing the fingerprint filter.

I've seen an example here - [Logstash Duplicate message](https://discuss.elastic.co/t/logstash-duplicate-message/26096)

which says:

filter {

uuid {  
target =\> "@uuid"  
overwrite =\> true  
}  
fingerprint {  
source =\> ["message"]  
target =\> "fingerprint"  
key =\> "78787878"  
method =\> "SHA1"  
concatenate\_sources =\> true  
}

What I'm not sure is what is that key? Should it be random, and do I have to place it. Would this exmaple help me with this?

Thanks

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### 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: [February 2, 2016, 10:49pm UTC](https://discuss.elastic.co/t/get-rid-of-duplicated-items/40630/2 "2016-02-02T22:49:46Z")

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Well the docs for `key` are kinda vague, so I can't help either 😛  
I've asked the LS dev team to see if they can help!

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### Author: ![nkoleff](https://avatars.discourse-cdn.com/v4/letter/n/d9b06d/32.png) [@nkoleff](https://discuss.elastic.co/u/nkoleff)
#### Post date: [February 3, 2016, 7:41am UTC](https://discuss.elastic.co/t/get-rid-of-duplicated-items/40630/3 "2016-02-03T07:41:53Z")

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indeed 🙂 thanks!

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### 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: [February 3, 2016, 10:10pm UTC](https://discuss.elastic.co/t/get-rid-of-duplicated-items/40630/4 "2016-02-03T22:10:36Z")

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The feedback I received was;

> in the context of the hashing algorithms, key is the hmac key used to generate to hash of the required value

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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: [July 6, 2017, 5:13am UTC](https://discuss.elastic.co/t/get-rid-of-duplicated-items/40630/5 "2017-07-06T05:13:08Z")

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