# Getting an error while running the logstash email output plugin - Unknown Garbage collector name- "G1 -Concurrent GC"

**URL:** <https://discuss.elastic.co/t/getting-an-error-while-running-the-logstash-email-output-plugin-unknown-garbage-collector-name-g1-concurrent-gc/340133>\
**Category:** Logstash\
**Created:** [August 4, 2023, 12:50pm UTC](https://discuss.elastic.co/t/getting-an-error-while-running-the-logstash-email-output-plugin-unknown-garbage-collector-name-g1-concurrent-gc/340133 "2023-08-04T12:50:38Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![AKCG23](https://avatars.discourse-cdn.com/v4/letter/a/f0a364/32.png) [@AKCG23](https://discuss.elastic.co/u/AKCG23)\
**Post date:** [August 4, 2023, 12:50pm UTC](https://discuss.elastic.co/t/getting-an-error-while-running-the-logstash-email-output-plugin-unknown-garbage-collector-name-g1-concurrent-gc/340133/1 "2023-08-04T12:50:38Z")

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I Have configured Logstash 7.17.3 and Heart beats 7.17.3. I am trying to send an email alert , if the url returns a code 401 .

I have configured the email output plugin. While running the logstash i get this error.

[2023-08-04T17:50:22,434][ERROR][logstash.instrument.periodicpoller.jvm] Unknown garbage collector name {:name=\>"G1 Concurrent GC"}  
[2023-08-04T17:50:27,475][ERROR][logstash.instrument.periodicpoller.jvm] Unknown garbage collector name {:name=\>"G1 Concurrent GC"}

Any help on this topic

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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:** [August 4, 2023, 2:47pm UTC](https://discuss.elastic.co/t/getting-an-error-while-running-the-logstash-email-output-plugin-unknown-garbage-collector-name-g1-concurrent-gc/340133/2 "2023-08-04T14:47:18Z")

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If you are using the bundled JDK then that is probably a bug. Otherwise it is just how things work. logstash wants to collect information about the garbage collector, since it is useful performance information, but it does not know about every GC algorithm. For example, if I add

```
17:-XX:+UseShenandoahGC

```

to /etc/logstash/jvm.options then the JVM will run Shenandoah, but logstash will log

```auto
[2023-08-04T10:35:40,026][ERROR][logstash.instrument.periodicpoller.jvm] Unknown garbage collector name {:name=>"Shenandoah Pauses"}
[2023-08-04T10:35:40,028][ERROR][logstash.instrument.periodicpoller.jvm] Unknown garbage collector name {:name=>"Shenandoah Cycles"}

```

every five seconds. It just is. `curl -XGET 'localhost:9600/_node/jvm?pretty'` works just fine. Not sure if stack monitoring includes detailed GC information anywhere. If it does then it will probably be missing.

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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:** [September 1, 2023, 2:47pm UTC](https://discuss.elastic.co/t/getting-an-error-while-running-the-logstash-email-output-plugin-unknown-garbage-collector-name-g1-concurrent-gc/340133/3 "2023-09-01T14:47:55Z")

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