"Your settings are invalid. Setting "" doesnt exist" error during setup

[dsilvera (David S)]

Setting up ELK 8.3.1 on Windows 10 PC and got Elastic Search and Kabana up and running. Reached to setting up logstash, entered the following command:

.\bin\logstash.bat -e "input { stdin { } } output { stdout {} }"

from the docs Stashing Your First Event | Logstash Reference [8.11] | Elastic
and got the following error:

c:\elasticstack\logstash\bin>logstash.bat -e "input { stdin { } } output { stdout {} }"
"Using bundled JDK: c:\elasticstack\logstash\jdk\bin\java.exe"
OpenJDK 64-Bit Server VM warning: Option UseConcMarkSweepGC was deprecated in version 9.0 and will likely be removed in a future release.
Sending Logstash logs to c:/elasticstack/logstash/logs which is now configured via log4j2.properties
[2022-07-03T10:41:46,249][INFO ][logstash.runner          ] Log4j configuration path used is: c:\elasticstack\logstash\config\log4j2.properties
[2022-07-03T10:41:46,254][INFO ][logstash.runner          ] Starting Logstash {"logstash.version"=>"8.3.1", "jruby.version"=>"jruby 9.2.20.1 (2.5.8) 2021-11-30 2a2962fbd1 OpenJDK 64-Bit Server VM 11.0.15+10 on 11.0.15+10 +indy +jit [mswin32-x86_64]"}
[2022-07-03T10:41:46,255][INFO ][logstash.runner          ] JVM bootstrap flags: [-Xms1g, -Xmx1g, -XX:+UseConcMarkSweepGC, -XX:CMSInitiatingOccupancyFraction=75, -XX:+UseCMSInitiatingOccupancyOnly, -Djava.awt.headless=true, -Dfile.encoding=UTF-8, -Djruby.compile.invokedynamic=true, -Djruby.jit.threshold=0, -XX:+HeapDumpOnOutOfMemoryError, -Djava.security.egd=file:/dev/urandom, -Dlog4j2.isThreadContextMapInheritable=true, -Djruby.regexp.interruptible=true, -Djdk.io.File.enableADS=true, --add-opens=java.base/java.security=ALL-UNNAMED, --add-opens=java.base/java.io=ALL-UNNAMED, --add-opens=java.base/java.nio.channels=ALL-UNNAMED, --add-opens=java.base/sun.nio.ch=ALL-UNNAMED, --add-opens=java.management/sun.management=ALL-UNNAMED]
Your settings are invalid. Reason: Setting "" doesn't exist. Please check if you haven't made a typo.
[2022-07-03T10:41:46,326][FATAL][org.logstash.Logstash    ] Logstash stopped processing because of an error: (SystemExit) exit
org.jruby.exceptions.SystemExit: (SystemExit) exit
        at org.jruby.RubyKernel.exit(org/jruby/RubyKernel.java:747) ~[jruby.jar:?]
        at org.jruby.RubyKernel.exit(org/jruby/RubyKernel.java:710) ~[jruby.jar:?]
        at c_3a_.elasticstack.logstash.lib.bootstrap.environment.<main>(c:\elasticstack\logstash\lib\bootstrap\environment.rb:91) ~[?:?]

It looks like an easy fix. Maybe it can't find some java settings? But I'm new at this.
Appreciate any help.

[Badger]

It's not about the Java settings. The JVM is up and running when this error is logged. Setting --log.level DEBUG might help narrow down what it is doing.

[dsilvera (David S)]

Well, this is extremely weird. Ran the following command:

@dsilvera

.\bin\logstash.bat -e "input { stdin { } } output { stdout {} }" --log.level "debug"

And it produced a lot of debug info, but kept outputting repetitive debug info. As if logstash was actually running.

So I stopped it with Ctrl+C and ran the command without debug on, and it worked fine.

I don't know what happened but it works now.
Thanks @Badger