# Logstash using custom Java

**URL:** <https://discuss.elastic.co/t/logstash-using-custom-java/149763>\
**Category:** Logstash\
**Created:** [September 25, 2018, 5:04am UTC](https://discuss.elastic.co/t/logstash-using-custom-java/149763 "2018-09-25T05:04:37Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![serozhka](https://avatars.discourse-cdn.com/v4/letter/s/73ab20/32.png) [@serozhka](https://discuss.elastic.co/u/serozhka)\
**Post date:** [September 25, 2018, 5:04am UTC](https://discuss.elastic.co/t/logstash-using-custom-java/149763/1 "2018-09-25T05:04:37Z")

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Hi guys!  
I have a Linux (RHEL) server, where I have to use logstash 6 in order to send log files to Kafka. Unfortunately, I dont have sudo there, also it has Java 1.7 and it is difficult to upgrade since these are production servers.  
I am running logstash from home directory, and I cannot find info how can I set it to be started with custom Java. I.e. startup-options config file doesnt work for me, because it is needed for startup and not for running instance.  
What I can do - I can extract Java 1.8 and then to try run Logstash.  
So my question is - how to bypass custom Java to start Logstash? Is it possible not to start Logstash with system defined Java?  
E.g. i want to achieve smth like "bin/logstash -f logstash.conf JAVA\_HOME=/home/myuser/somejdk/java". Or if this doesnt work, maybe Java can be defined in some config file, but I wasnt able to find out in which.

P.S. Some time ago I sucessfully started Logstash towards Kafka on other RHEL where Java 1.8 resides.

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**Author:** ![magnusbaeck](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/magnusbaeck/32/44943_2.png) [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)\
**Post date:** [September 25, 2018, 9:15am UTC](https://discuss.elastic.co/t/logstash-using-custom-java/149763/2 "2018-09-25T09:15:22Z")

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Have you tried `JAVA_HOME=/home/myuser/somejdk/java bin/logstash -f logstash.conf`?

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**Author:** ![serozhka](https://avatars.discourse-cdn.com/v4/letter/s/73ab20/32.png) [@serozhka](https://discuss.elastic.co/u/serozhka)\
**Post date:** [September 25, 2018, 10:00am UTC](https://discuss.elastic.co/t/logstash-using-custom-java/149763/3 "2018-09-25T10:00:34Z")

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Yes, it doesnt make any sence, it still runs with system-wide Java (1.7):  
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/logstash/Logstash : Unsupported major.minor version 52.0

Even if I run JAVA\_HOME=/some/unexisting/folder bin/logstash -f logstash.conf &, it still uses system Java.

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**Author:** ![serozhka](https://avatars.discourse-cdn.com/v4/letter/s/73ab20/32.png) [@serozhka](https://discuss.elastic.co/u/serozhka)\
**Post date:** [September 25, 2018, 11:41am UTC](https://discuss.elastic.co/t/logstash-using-custom-java/149763/4 "2018-09-25T11:41:42Z")

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I have found way how to start it. Correct command is:

JAVA\_HOME="/your/java/path/to/jre" bin/logstash -f logstash.conf &

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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:** [October 23, 2018, 11:41am UTC](https://discuss.elastic.co/t/logstash-using-custom-java/149763/5 "2018-10-23T11:41:45Z")

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