Feature Request - Logstash needs an always read end of file option

Request for a parameter to force Logstash to always read the end of the latest file whether it is an existing already read file or a new one eg after a Logstash restart it will ignore any sincedb_path setting and just read the end of the latest file.

The only current out-of-the-box method to force Logstash to read the end of an old or new file seems to be to set the flag start_position => "end" (default value) and remember to delete that sincedb_path file before starting up Logstash which requires manual intervention or a bespoke startup script.