Akeeba Backup gets around PHP timeout issues by doing the backup in tiny steps. It does as much as possible in one step, then saves a "bookmark" so it knows where it left off, then starts a new step with a new timer. This backup was interrupted because it could not save the bookmark. We really can't tell from the log if that is the cause of the problem or if it is a symptom of something else.
Please go to Configuration and flip the value of the "Use database storage for temporary data" field. If it is checked, uncheck it, if it is unchecked, check it. That changes how the bookmark is stored. Since this is an intermittent problem, you may have to test if for a few days to know if the problem is fixed. Please let me know.
Dale L. Brackin
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!
My time zone is EST (UTC -5) (click here to see my current time in Philadelphia, PA)