If you find yourself setting MAX_EVENTS to be very large, you should probably consider changing the LINE_BREAKER to break the input stream into larger chunks (that aren't single lines).
At index time, data is broken into lines (usually by \r\n or \n). It then may be put back together using line merging. It's significantly more efficient to not have to reassemble the data with string concatenation. You then have to set the maximum "line" length using the TRUNCATE attribute. If you know that every event is demarcated by two newlines, you could set in props.conf: