:error=>#<ArgumentError: Setting "" hasn't been registered> from logstash v5.5.0

[gayathri (Gayathri TR)]

Hi Team,

We are getting below error while starting logstash 5.5.0 from bin:

[2018-05-23T05:09:47,737][FATAL][logstash.runner ] An unexpected error occurred! {:error=>#<ArgumentError: Setting "" hasn't been registered>, :backtrace=>["/opt/logstash-5.5.0/logstash-core/lib/logstash/settings.rb:32:in get_setting'", "/opt/logstash-5.5.0/logstash-core/lib/logstash/settings.rb:64:inset_value'", "/opt/logstash-5.5.0/logstash-core/lib/logstash/settings.rb:83:in merge'", "org/jruby/RubyHash.java:1342:ineach'", "/opt/logstash-5.5.0/logstash-core/lib/logstash/settings.rb:83:in merge'", "/opt/logstash-5.5.0/logstash-core/lib/logstash/settings.rb:135:invalidate_all'", "/opt/logstash-5.5.0/logstash-core/lib/logstash/runner.rb:244:in `execute'",

PFB, logstash configuration of the same:

input {
redis{
host => "localhost"
data_type => "list"
codec => "json"
}
}

}
output{
elasticsearch{
hosts => ["elastic_server:9200"]
index => "logstash-%{+YYYY.MM.dd}"
}
}

Regards,
Gayathri T R

[Badger]

Look very closely at your logstash.yml. "Setting hasn't been registered" means there is a line in the yml that has a name that no code has registered to process. If you add a line at the top of the yml that says " foo : bar" you would expect to get 'ArgumentError: Setting "foo" hasn't been registered'. I cannot think how you could get Setting "", but that's where I would start looking.