# Mutate lowercase filter not been applied

**URL:** <https://discuss.elastic.co/t/mutate-lowercase-filter-not-been-applied/212693>\
**Category:** Logstash\
**Created:** [December 20, 2019, 5:23pm UTC](https://discuss.elastic.co/t/mutate-lowercase-filter-not-been-applied/212693 "2019-12-20T17:23:31Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![francescouk](https://avatars.discourse-cdn.com/v4/letter/f/7feea3/32.png) [@francescouk](https://discuss.elastic.co/u/francescouk)\
**Post date:** [December 20, 2019, 5:23pm UTC](https://discuss.elastic.co/t/mutate-lowercase-filter-not-been-applied/212693/1 "2019-12-20T17:23:31Z")

</div>

Hello there,

Im trying to use the lowercase filter but it seens that is not working. I want to apply the filter on "TargetDomainName" field so the results should be "contoso\_rt" instead of "CONTOSO\_RT"

Can someone point me what I´m doing wrong?

Here is my config:

```
if [type] == "eventlog" {  
mutate {
    lowercase => ["TargetDomainName"]
}

```

Debug:

```
"winlog" => {
        "provider_name" => "Microsoft-Windows-Security-Auditing",
                 "task" => "Logon",
             "keywords" => [
            [0] "Audit Success"
        ],
              "channel" => "Security",
              "event_data" => {
                            "KeyLength" => "0",
                          "ProcessName" => "-",
                            "LogonType" => "3",
                        "LmPackageName" => "-",
                     "TargetDomainName" => "CONTOSO_RT",

```

Thanks for the attention,

Franthesco Ferrari

---

<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:** [December 20, 2019, 5:54pm UTC](https://discuss.elastic.co/t/mutate-lowercase-filter-not-been-applied/212693/2 "2019-12-20T17:54:08Z")

</div>

It looks like the field is not at the root, so you need to specify it fully, e.g. `lowercase => ["[winlog][event_data][TargetDomainName]" ]`.

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<div class="post-metadata">

**Author:** ![francescouk](https://avatars.discourse-cdn.com/v4/letter/f/7feea3/32.png) [@francescouk](https://discuss.elastic.co/u/francescouk)\
**Post date:** [December 20, 2019, 7:00pm UTC](https://discuss.elastic.co/t/mutate-lowercase-filter-not-been-applied/212693/3 "2019-12-20T19:00:55Z")

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Wow!!! You just saved my day!!!! Thanks for your help!! 🙂

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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:** [January 17, 2020, 7:09pm UTC](https://discuss.elastic.co/t/mutate-lowercase-filter-not-been-applied/212693/4 "2020-01-17T19:09:33Z")

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