logstash file input looses a lot of lines

I just used logstash on a file input - where we simply throw in finished files (they get uploaded from the router, at set intervals), and then we remove them after a couple of hours (to avoid running out of diskspace).

Problem was that with input { file { path => "/path/*", start_position => beginning } -it lost a lot of lines at set intervals, which seemed to fit with the size/time-window for each logfile.

It should be very easy to reproduce (throw a lot of lines in logfiles at it, and then compare counts to actual content in logfiles).

I had to get it working, so I figured I'd try something else to check for logfiles, and switched to using logstash-forwarder (aka. lumberjack) to handle it, and then just have a lumberjack input in logstash - and that works flawlessly.