Yes, ServiceAlive will notifiy you, if your periodic job (like cron) failed. This will happen, when Success reporting web-request to our heartbeatendpoint does not happen within expected period.
Configure your Heartbeats using the same monitor definition form by changing “Protocol” to “Heatbeat”. Then, set Interval value to maximum expected time between two consequitive heartbeats.
Also, please have a look on other cool features.