test5.conf

input {
    file {
        path => ["D:/ES/logstash-7.3.0/nginx.log"]        
        start_position => "beginning"
    }
}

filter {
  grok {
        match => { "message" => "%{IP:clientip}\ \[%{HTTPDATE:timestamp}\]\ %{QS:referrer}\ %{NUMBER:response}\ %{NUMBER:bytes}" }
        remove_field => [ "message" ]
   }
	date {
        match => ["timestamp", "dd/MMM/yyyy:HH:mm:ss Z"]
    }
	mutate {
           rename => { "response" => "response_new" }
           convert => [ "response","float" ]
           gsub => ["referrer","\"",""]
           remove_field => ["timestamp"]
           split => ["clientip", "."]
        }
}

output {
    elasticsearch {
        hosts => ["127.0.0.1:9200"]
        index => "logstash-%{+YYYY.MM.dd}"
    }
}