fluentd csv file tail

gistfile1.txt

<source>
  type tail
  tag app_csv_log_file_name
  format /^(?<column1>[^,]*),(?<column2>[^ ]*),(?<column3>[^ ]*),(?<column4>[^ ]*),(?<column5>[^ ]*)?$/

  path /var/log/app_log_dir/app_csv_log_file
  pos_file /var/log/td-agent/tmp/app_csv_log.pos
</source>

<match *.**>
    type forward
    <server>
        name aggregate
        host 192.168.1.1
        port 24224
        weight 60
    </server>
    buffer_type file
    buffer_path /var/log/td-agent/myapp-forward
    retry_limit 50
    flush_interval 1s
</match>