Re-running /opt/logstash/bin/logstash with same conf file does not produce output

Using logstash v2.3.2

I have a *.conf file that I use for this command

/opt/logstash/bin/logstash -f /path/mylogstash.conf

I was able to run this yesterday and was able to produce my desired mylogstash.json output file. I then logged out of the logstash server, and went home for the day.

Today, I logged back in the logstash server, deleted my mylogstash.json output file, and the ~/.sincedb* file. I then re-ran the above command, but did NOT get an output file.

What would cause this, that is, logstash producing an output JSON file one day, and not the next day, using the same *.conf file?

Thanks

Perhaps the input file is older than 24 hours and you didn't set the file input's ignore_older option to accommodate that?

@magnusbaeck thanks! Just for testing, I set it to ignore_older => 0 and was able to read the file. I also did set sincedb_path => "/dev/null"