Warnings on logstash's config execution - "A gauge metric of an unknown type (org.jruby.RubySymbol) has been created for key: status"

[Shreesh_Narayanan]

Hello,

I see the below warnings on logstash , only when a particular config is used. The warning is as below

[2021-08-10T17:26:22,581][WARN ][org.logstash.instrument.metrics.gauge.LazyDelegatingGauge][main] A gauge metric of an unknown type (org.jruby.RubySymbol) has been created for key: status. This may result in invalid serialization.  It is recommended to log an issue to the responsible developer/development team.
[2021-08-10T17:26:22,586][WARN ][org.logstash.instrument.metrics.gauge.LazyDelegatingGauge][main] A gauge metric of an unknown type (org.jruby.RubySymbol) has been created for key: status. This may result in invalid serialization.  It is recommended to log an issue to the responsible developer/development team.
[2021-08-10T17:26:22,608][WARN ][org.logstash.instrument.metrics.gauge.LazyDelegatingGauge] A gauge metric of an unknown type (org.jruby.RubySymbol) has been created for key: status. This may result in invalid serialization.  It is recommended to log an issue to the responsible developer/development team.

Here's the Input section :

input {
file  {
path => "/app/input/ghost.ddc*.*"
mode => "read"
sincedb_path => "/dev/null"
file_completed_action => "log"
file_completed_log_path => "/app/processed/output.txt"
}
#stdin {}
      }

and the output

output
        {
                elasticsearch
                                {
                                        hosts => [ "172.26.207.164:9200" ]
                                        index => "logstash_ghost"
                                        user => "elastic"
                                        password => "${ES_PWD}"
                                }
#       stdout {}

}
                                               

The other config doesn't show this warning , it doesn;t have any negative impact . But still would like to know why it shows up in this config only.