Hi @Dheeraj_Gupta
I did thought that could be an issue considering the error that i got, the above error message was with the absolute path of csv file itself.
Below is the error that i got with relative path of the file,
[2018-09-10T15:28:14,511][WARN ][logstash.config.source.multilocal] Ignoring the 'pipelines.yml' file because modules or command line options are specified
[2018-09-10T15:28:15,769][INFO ][logstash.runner ] Starting Logstash {"logstash.version"=>"6.4.0"}
[2018-09-10T15:28:23,120][INFO ][logstash.pipeline ] Starting pipeline {:pipeline_id=>"main", "pipeline.workers"=>4, "pipeline.batch.size"=>125, "pipeline.batch.delay"=>50}
[2018-09-10T15:28:23,732][INFO ][logstash.outputs.elasticsearch] Elasticsearch pool URLs updated {:changes=>{:removed=>[], :added=>[http://localhost:9200/]}}
[2018-09-10T15:28:23,745][INFO ][logstash.outputs.elasticsearch] Running health check to see if an Elasticsearch connection is working {:healthcheck_url=>http://localhost:9200/, :path=>"/"}
[2018-09-10T15:28:24,087][WARN ][logstash.outputs.elasticsearch] Restored connection to ES instance {:url=>"http://localhost:9200/"}
[2018-09-10T15:28:24,177][INFO ][logstash.outputs.elasticsearch] ES Output version determined {:es_version=>6}
[2018-09-10T15:28:24,177][WARN ][logstash.outputs.elasticsearch] Detected a 6.x and above cluster: the `type` event field won't be used to determine the document _type {:es_version=>6}
[2018-09-10T15:28:24,217][INFO ][logstash.outputs.elasticsearch] New Elasticsearch output {:class=>"LogStash::Outputs::ElasticSearch", :hosts=>["http://localhost:9200"]}
[2018-09-10T15:28:24,247][INFO ][logstash.outputs.elasticsearch] Using mapping template from {:path=>nil}
[2018-09-10T15:28:24,267][INFO ][logstash.outputs.elasticsearch] Attempting to install template {:manage_template=>{"template"=>"logstash-*", "version"=>60001, "settings"=>{"index.refresh_interval"=>"5s"}, "mappings"=>{"_default_"=>{"dynamic_templates"=>[{"message_field"=>{"path_match"=>"message", "match_mapping_type"=>"string", "mapping"=>{"type"=>"text", "norms"=>false}}}, {"string_fields"=>{"match"=>"*", "match_mapping_type"=>"string", "mapping"=>{"type"=>"text", "norms"=>false, "fields"=>{"keyword"=>{"type"=>"keyword", "ignore_above"=>256}}}}}], "properties"=>{"@timestamp"=>{"type"=>"date"}, "@version"=>{"type"=>"keyword"}, "geoip"=>{"dynamic"=>true, "properties"=>{"ip"=>{"type"=>"ip"}, "location"=>{"type"=>"geo_point"}, "latitude"=>{"type"=>"half_float"}, "longitude"=>{"type"=>"half_float"}}}}}}}}
[2018-09-10T15:28:25,088][ERROR][logstash.pipeline ] Error registering plugin {:pipeline_id=>"main", :plugin=>"<LogStash::Inputs::File start_position=>\"beginning\", path=>[\"cars.csv\"], id=>\"882ab898345c77e2d2dfb1a70981b4329a808edaabbf190f6ee058234e7b4f09\", sincedb_path=>\"/dev/null\", enable_metric=>true, codec=><LogStash::Codecs::Plain id=>\"plain_d4c9e5cb-27a9-408b-a638-949060522f4a\", enable_metric=>true, charset=>\"UTF-8\">, stat_interval=>1.0, discover_interval=>15, sincedb_write_interval=>15.0, delimiter=>\"\\n\", close_older=>3600.0, mode=>\"tail\", file_completed_action=>\"delete\", sincedb_clean_after=>1209600.0, file_chunk_size=>32768, file_chunk_count=>140737488355327, file_sort_by=>\"last_modified\", file_sort_direction=>\"asc\">", :error=>"File paths must be absolute, relative path specified: cars.csv", :thread=>"#<Thread:0x1661e610 run>"}
[2018-09-10T15:28:25,217][ERROR][logstash.pipeline ] Pipeline aborted due to error {:pipeline_id=>"main", :exception=>#<ArgumentError: File paths must be absolute, relative path specified: cars.csv>, :backtrace=>["C:/logstash/vendor/bundle/jruby/2.3.0/gems/logstash-input-file-4.1.5/lib/logstash/inputs/file.rb:269:in `block in register'", "org/jruby/RubyArray.java:1734:in `each'", "C:/logstash/vendor/bundle/jruby/2.3.0/gems/logstash-input-file-4.1.5/lib/logstash/inputs/file.rb:267:in `register'", "C:/logstash/logstash-core/lib/logstash/pipeline.rb:241:in `register_plugin'", "C:/logstash/logstash-core/lib/logstash/pipeline.rb:252:in `block in register_plugins'", "org/jruby/RubyArray.java:1734:in `each'", "C:/logstash/logstash-core/lib/logstash/pipeline.rb:252:in `register_plugins'", "C:/logstash/logstash-core/lib/logstash/pipeline.rb:395:in `start_inputs'", "C:/logstash/logstash-core/lib/logstash/pipeline.rb:293:in `start_workers'", "C:/logstash/logstash-core/lib/logstash/pipeline.rb:199:in `run'", "C:/logstash/logstash-core/lib/logstash/pipeline.rb:159:in `block in start'"], :thread=>"#<Thread:0x1661e610 run>"}
[2018-09-10T15:28:25,239][ERROR][logstash.agent ] Failed to execute action {:id=>:main, :action_type=>LogStash::ConvergeResult::FailedAction, :message=>"Could not execute action: PipelineAction::Create<main>, action_result: false", :backtrace=>nil}
[2018-09-10T15:28:25,739][INFO ][logstash.agent ] Successfully started Logstash API endpoint {:port=>9600}
Note: I have Config file & CSV Data within the same folder, whereas Logstash is installed in another drive.