filter {
      mutate {
        # Renames the 'HOSTORIP' field to 'client_ip'
        rename => { "HOSTORIP" => "client_ip" }
        convert => {
                "fieldname" => "integer"
            "booleanfield" => "boolean"
        }
        copy => { "source_field" => "dest_field" }
        split => { "fieldname" => "," }
      }
    }