AWS CloudWatch FAQ

AWS CloudWatch

Q: What is the minimum time interval granularity for the data that Amazon CloudWatch receives and aggregates?

Metrics are received and aggregated at 1 minute intervals.

Q: Which operating systems does Amazon CloudWatch support?

Amazon CloudWatch receives and provides metrics for all Amazon EC2 instances and should work with any operating system currently supported by the Amazon EC2 service.

Q: Will I lose the metrics data if I disable monitoring for an Amazon EC2 instance?

You can retrieve metrics data for any Amazon EC2 instance up to 2 weeks from the time you started to monitor it. After 2 weeks, metrics data for an Amazon EC2 instance will not be available if monitoring was disabled for that Amazon EC2 instance. If you want to archive metrics beyond 2 weeks you can do so by calling mon-get-stats command from the command line and storing the results in Amazon S3 or Amazon SimpleDB.

Q: Can I access the metrics data for a terminated Amazon EC2 instance or a deleted Elastic Load Balancer?

Yes. Amazon CloudWatch stores metrics for terminated Amazon EC2 instances or deleted Elastic Load Balancers for 2 weeks.

Q: Does the Amazon CloudWatch monitoring charge change depending on which type of Amazon EC2 instance I monitor?

No, the Amazon CloudWatch monitoring charge does not vary by Amazon EC2 instance type.

Q: Why does the graphing of the same time window look different when I view in 5 minute and 1 minute periods?

If you view the same time window in a 5 minute period versus a 1 minute period, you may see that data points are displayed in different places on the graph. For the period you specify in your graph, Amazon CloudWatch will find all the available data points and calculates a single, aggregate point to represent the entire period. In the case of a 5 minute period, the single data point is placed at the beginning of the 5 minute time window. In the case of a 1 minute period, the single data point is placed at the 1 minute mark. We recommend using a 1 minute period for troubleshooting and other activities that require the most precise graphing of time periods.