A fundamental characteristic of a modern monitoring system is the Alerting subsistem.
Thank to it an alerting message on devices, systems or applications fault can be sent.
Traditional monitoring platforms are using a Reactive event handling system that as soon as the monitored item works in a wrong way is able to send a message to the IT administrator through the available channels.
This is a huge step forward compared to the lack of a system of this kind, before it's adoption customers called the IT department complaining about a malfuncioning, now the monitoring system warn in real time IT administrators and when the customer calls the IT department (maybe) the problem is still solved.
Of course, now it all depends on the speed with which the system administrators are able to solve the problem!
Each Manager has a deep knowledge of his infrastructure and often when a problem arises he already knows what actions have to be performed to solve it.
Often he has already created scripts that automate recovery procedures.
Proactive monitoring is crucial in these situations.
A proactive monitoring system once a problematic event occurres is able to perform automatic procedures, such as the scripts created by the administrator, to fix it.
First with a reactive system was the administrator who was alerted and then he should fix the problem, now the monitoring system replaces the administrator and automatically starts the recovery procedures. Probably the administrator will detects a malfunction when it has already been solved!
But what happens if the system is not able to solve the problem?
In this case, the administrator is warned that the procedure set has not had the desired effect and thus that the "usual cause of the malfunction" is not so usual! Now the problem has another cause.
It 'important to note that even in this situation the proactive system had its effectiveness, in fact the administrator is immediately notified that the cause is not the usual and he will save all the time that he would lose by running its usual troubleshooting steps.