I am new to logstash. Getting the error below. Any thoughts appreciated.
ubuntu@ip-172-31-32-110:~/Downloads/logstash-5.6.4$ bin/logstash -f "helpdesk.config"
Sending Logstash's logs to /home/ubuntu/Downloads/logstash-5.6.4/logs which is now configured via log4j2.properties
[2017-11-13T14:52:56,499][INFO ][logstash.modules.scaffold] Initializing module {:module_name=>"fb_apache", :directory=>"/home/ubuntu/Downloads/logstash-5.6.4/modules/fb_apache/configuration"}
[2017-11-13T14:52:56,504][INFO ][logstash.modules.scaffold] Initializing module {:module_name=>"netflow", :directory=>"/home/ubuntu/Downloads/logstash-5.6.4/modules/netflow/configuration"}
[2017-11-13T14:52:57,134][INFO ][logstash.outputs.elasticsearch] Elasticsearch pool URLs updated {:changes=>{:removed=>[], :added=>[http://localhost:9200/]}}
[2017-11-13T14:52:57,135][INFO ][logstash.outputs.elasticsearch] Running health check to see if an Elasticsearch connection is working {:healthcheck_url=>http://localhost:9200/, :path=>"/"}
[2017-11-13T14:52:57,215][WARN ][logstash.outputs.elasticsearch] Restored connection to ES instance {:url=>"http://localhost:9200/"}
[2017-11-13T14:52:57,250][INFO ][logstash.outputs.elasticsearch] Using mapping template from {:path=>nil}
[2017-11-13T14:52:57,254][INFO ][logstash.outputs.elasticsearch] Attempting to install template {:manage_template=>{"template"=>"logstash-", "settings"=>{"index.refresh_interval"=>"5s"}, "mappings"=>{"default"=>{"_all"=>{"enabled"=>true, "omit_norms"=>true}, "dynamic_templates"=>[{"message_field"=>{"path_match"=>"message", "match_mapping_type"=>"string", "mapping"=>{"type"=>"string", "index"=>"analyzed", "omit_norms"=>true, "fielddata"=>{"format"=>"disabled"}}}}, {"string_fields"=>{"match"=>"", "match_mapping_type"=>"string", "mapping"=>{"type"=>"string", "index"=>"analyzed", "omit_norms"=>true, "fielddata"=>{"format"=>"disabled"}, "fields"=>{"raw"=>{"type"=>"string", "index"=>"not_analyzed", "doc_values"=>true, "ignore_above"=>256}}}}}, {"float_fields"=>{"match"=>"", "match_mapping_type"=>"float", "mapping"=>{"type"=>"float", "doc_values"=>true}}}, {"double_fields"=>{"match"=>"", "match_mapping_type"=>"double", "mapping"=>{"type"=>"double", "doc_values"=>true}}}, {"byte_fields"=>{"match"=>"", "match_mapping_type"=>"byte", "mapping"=>{"type"=>"byte", "doc_values"=>true}}}, {"short_fields"=>{"match"=>"", "match_mapping_type"=>"short", "mapping"=>{"type"=>"short", "doc_values"=>true}}}, {"integer_fields"=>{"match"=>"", "match_mapping_type"=>"integer", "mapping"=>{"type"=>"integer", "doc_values"=>true}}}, {"long_fields"=>{"match"=>"", "match_mapping_type"=>"long", "mapping"=>{"type"=>"long", "doc_values"=>true}}}, {"date_fields"=>{"match"=>"", "match_mapping_type"=>"date", "mapping"=>{"type"=>"date", "doc_values"=>true}}}, {"geo_point_fields"=>{"match"=>"", "match_mapping_type"=>"geo_point", "mapping"=>{"type"=>"geo_point", "doc_values"=>true}}}], "properties"=>{"@timestamp"=>{"type"=>"date", "doc_values"=>true}, "@version"=>{"type"=>"string", "index"=>"not_analyzed", "doc_values"=>true}, "geoip"=>{"type"=>"object", "dynamic"=>true, "properties"=>{"ip"=>{"type"=>"ip", "doc_values"=>true}, "location"=>{"type"=>"geo_point", "doc_values"=>true}, "latitude"=>{"type"=>"float", "doc_values"=>true}, "longitude"=>{"type"=>"float", "doc_values"=>true}}}}}}}}
[2017-11-13T14:52:57,259][INFO ][logstash.outputs.elasticsearch] New Elasticsearch output {:class=>"LogStash::Outputs::ElasticSearch", :hosts=>["http://localhost:9200"]}
[2017-11-13T14:52:57,263][ERROR][logstash.pipeline ] Error registering plugin {:plugin=>"#<LogStash::FilterDelegator:0x5223bdbe @metric_events_out=LogStash::Instrument::MetricType::Counter - namespaces: [:stats, :pipelines, :main, :plugins, :filters, :"7394efbfc3fd82c08fe4532836c8a44e33c5f621-3", :events] key: out value: 0, @metric_events_in=LogStash::Instrument::MetricType::Counter - namespaces: [:stats, :pipelines, :main, :plugins, :filters, :"7394efbfc3fd82c08fe4532836c8a44e33c5f621-3", (more...)