Persist Last Image

Hi all. Recently we have such a need in our project. We would like to always
persist the last sent message. So in case of a system failure, we would be
able to recover the message and resend to the consumer once they are
reconnected.

My plan was to save the message right after it was sent and by doing in a
rolling fashion, there is always the last message on the disk. However, this
method seems not right.

Does anyone have an idea how this could be done?