Monitoring

The act of collecting, analyzing, and using data to make decisions or answer questions about your IT resources and systems is called monitoring.

Metrics

Each individual data point that is created by a resource is a metric. Metrics that are collected and analyzed over time become statistics.

The metrics can be:

• CPU utilization
• network utilization
• disk performance
• memory utilization
• logs created by the applications running on top of EC2

Alarm

To set up an alarm you need to choose:

• the metric
• the threshold
• the time period

For example, if you wanted to set up an alarm for an EC2 instance to trigger when the CPU utilization goes over a threshold of 80%, you also need to specify the time period the CPU utilization is over the threshold. For example if it is over 80% for 5 minutes or longer, when there is a potential resource issue.