How do I use Amazon EFS metrics?

The metrics reported by Amazon EFS provide information that you can analyze in different ways. The following list shows some common uses for the metrics. These are suggestions to get you started, not a comprehensive list.

How do I?	Relevant metrics
How can I determine my throughput?	You can monitor the daily Sum statistic of the TotalIOBytes metric to see your throughput.
How can I track the number of Amazon EC2 instances that are connected to a file system?	You can monitor the Sum statistic of the ClientConnections metric. To calculate the average ClientConnections for periods greater than one minute, divide the sum by the number of minutes in the period.
How can I see my burst credit balance?	You can see your balance by monitoring the BurstCreditBalance metric for your file system. For more information on bursting and burst credits, see Bursting Throughput mode.

Using CloudWatch metrics to monitor throughput performance

The Amazon EFS CloudWatch metrics for throughput monitoring—TotalIOBytes, ReadIOBytes, WriteIOBytes, and MetadataIOBytes—represent the actual throughput that you are driving on your file system. The metric MeteredIOBytes represents the calculation of the overall metered throughput that you are driving. You can use the Throughput utilization (%) graph in the Amazon EFS console Monitoring section to monitor your throughput utilization. If you use custom Amazon CloudWatch dashboards or another monitoring tool, you can create a CloudWatch metric math expression that compares MeteredIOBytes to PermittedThroughput.

PermittedThroughput measures the amount of allowed throughput for the file system. This value is based on one of the following methods:

• For file systems in Provisioned Throughput mode, if the amount of data stored in the EFS Standard storage class allows your file system to drive a higher throughput than you provisioned, this metric reflects the higher throughput instead of the provisioned amount.

• For file systems in Bursting Throughput mode, this value is a function of the file system size and BurstCreditBalance.

When the values for MeteredIOBytes and PermittedThroughput are equal, your file system is consuming all available throughput. For file systems using Provisioned Throughput mode, you can provision additional throughput.

For file systems using Bursting Throughput mode, monitor BurstCreditBalance to ensure that your file system is operating at its burst rate rather than its base rate. If the balance is consistently at or near zero, you must switch to Provisioned Throughput mode to get additional throughput.