Related to the main topic - I'm getting this now after upgrading to 4.1.2. Should I take any action or is this some bug?
[2018-05-04T09:52:50,706][INFO ][filewatch.tailmode.handlers.grow] buffer_extract: a delimiter can't be found in current chunk, maybe there are no more delimiters or the delimiter is incorrect or the text before the delimiter, a 'line', is very large, if this message is logged often try increasing the `file_chunk_size` setting. {"delimiter"=>"\n", "read_position"=>827326, "bytes_read_count"=>66, "last_known_file_size"=>827392, "file_path"=>"/foo/bar/my.log"}
FYI, I got this error while doing some testing in relation to this topic: Logstash 6.2.1 Big .since-db file causes OutOfMemory - and added a reply there.