Specifically in the case of a single source and sink attached to the channel... I know that in Flume we do not explicitly guarantee FIFO order for any of the channels although in practice the channels do seem to exhibit FIFO.
Specifically wrt to file channel... Not sure if under normal operation (I.e source and sink are not experiencing issues causing them to abort TXNs) FIFO ordering can be lost. But...maybe the order can be lost if the single sink is experiencing lot of issues leading to repeatedly aborting TXNs for an extended period of time. Possible ?? Or perhaps there are other known edge cases when FIFO order can be lost ? -roshan
