# Could not determine ID for filter/useragent

**URL:** <https://discuss.elastic.co/t/could-not-determine-id-for-filter-useragent/294270>\
**Category:** Logstash\
**Created:** [January 13, 2022, 12:03pm UTC](https://discuss.elastic.co/t/could-not-determine-id-for-filter-useragent/294270 "2022-01-13T12:03:26Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![Chris\_Andrews](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/chris_andrews/32/100266_2.png) [@Chris\_Andrews](https://discuss.elastic.co/u/Chris_Andrews)\
**Post date:** [January 13, 2022, 12:03pm UTC](https://discuss.elastic.co/t/could-not-determine-id-for-filter-useragent/294270/1 "2022-01-13T12:03:26Z")

</div>

We have upgraded logstash from 7.5.2 to 7.16.2 on three separate instances. The first two upgraded with no issues whatsoever, however the final upgrade encountered this problem and now logstash crashes:

Stack trace:

```auto
[2022-01-13T11:54:52,979][ERROR][logstash.agent] Failed to execute action {:action=>LogStash::PipelineAction::Create/
pipeline_id:main, :exception=>"LogStash::ConfigurationError", :message=>"Could not determine ID for filter/useragent", :backtrac
e=>["org/logstash/plugins/factory/PluginFactoryExt.java:221:in `plugin'", "org/logstash/plugins/factory/PluginFactoryExt.java:203:in `plugin'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:99:in `plugin'", "(eval):166193:in `initialize'", "org/jruby/RubyKernel.java:1048:in `eval'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:73:in `initialize'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:118:in `initialize'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline_action/create.rb:52:in `execute'", "/usr/share/logstash/logstash-core/lib/logstash/agent.rb:383:in `block in converge_state'"]}

```

The configuration files are exactly the same on all three instances which makes this extra odd.

Any ideas on what I can try and rule out? According to the docs the id's for filters should be auto generated, but that error seems to suggest they are not.

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<div class="post-metadata">

**Author:** ![AquaX](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/aquax/32/92006_2.png) [@AquaX](https://discuss.elastic.co/u/AquaX)\
**Post date:** [January 14, 2022, 5:11pm UTC](https://discuss.elastic.co/t/could-not-determine-id-for-filter-useragent/294270/2 "2022-01-14T17:11:03Z")

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> [@Chris\_Andrews](#):
>
> `Could not determine ID for filter/useragent`

Can you try manually defining an id?

> **[Useragent filter plugin | Logstash Reference \[8.11\] | Elastic](https://www.elastic.co/guide/en/logstash/current/plugins-filters-useragent.html#plugins-filters-useragent-id)**

Not sure why it wouldn't work on this instance when it works on others.  
But when having multiple logstash filters it's good practice to define your own id's as it makes troubleshooting much easier.

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<div class="post-metadata">

**Author:** ![Chris\_Andrews](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/chris_andrews/32/100266_2.png) [@Chris\_Andrews](https://discuss.elastic.co/u/Chris_Andrews)\
**Post date:** [January 17, 2022, 1:38pm UTC](https://discuss.elastic.co/t/could-not-determine-id-for-filter-useragent/294270/3 "2022-01-17T13:38:42Z")

</div>

If I do that then it complains about a different filter with the same error. It's as though the automatic ID generation isn't working.

Also due to the size of our configuration it isn't realistic to add ID fields everywhere.

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<div class="post-metadata">

**Author:** ![Badger](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/badger/32/25190_2.png) [@Badger](https://discuss.elastic.co/u/Badger)\
**Post date:** [January 17, 2022, 3:35pm UTC](https://discuss.elastic.co/t/could-not-determine-id-for-filter-useragent/294270/4 "2022-01-17T15:35:31Z")

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> [@Chris\_Andrews](#):
>
> `Could not determine ID for filter/useragent`

Are you certain the configurations are identical? It could be an issue like [this](https://github.com/elastic/logstash/issues/12155) one, where a trailing newline causes that error.

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<div class="post-metadata">

**Author:** ![Chris\_Andrews](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/chris_andrews/32/100266_2.png) [@Chris\_Andrews](https://discuss.elastic.co/u/Chris_Andrews)\
**Post date:** [January 25, 2022, 8:39pm UTC](https://discuss.elastic.co/t/could-not-determine-id-for-filter-useragent/294270/5 "2022-01-25T20:39:21Z")

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Thank you! That is exactly what the problem was - A newline character in a configuration file.

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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:** [February 22, 2022, 8:39pm UTC](https://discuss.elastic.co/t/could-not-determine-id-for-filter-useragent/294270/6 "2022-02-22T20:39:46Z")

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