flink cep and out of order events

[Jin Yi <ji...@promoted.ai>]

does the default within behavior of flink cep handle out of order events
(relative to event time)?  obviously, it'd be best if the event time was
guaranteed correct, but sometimes it's too difficult to do.

do people end up writing different patterns with some event orderings
reversed to capture these out of order events and push
unmatched/partial/timed-out events from side channels off the main pattern
matching through this?

is it better to invest in some pre-processing to try and guarantee ordering?