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Amazon Elastic File System
User Guide

Monitoring with Amazon CloudWatch

You can monitor file systems using Amazon CloudWatch, which collects and processes raw data from Amazon EFS into readable, near real-time metrics. These statistics are recorded for a period of 15 months, so that you can access historical information and gain a better perspective on how your web application or service is performing. By default, Amazon EFS metric data is automatically sent to CloudWatch at 1-minute periods. For more information about CloudWatch, see What Are Amazon CloudWatch, Amazon CloudWatch Events, and Amazon CloudWatch Logs? in the Amazon CloudWatch User Guide.

Amazon CloudWatch Metrics for Amazon EFS

The AWS/EFS namespace includes the following metrics.

Metric Description
BurstCreditBalance

The number of burst credits that a file system has.

Burst credits allow a file system to burst to throughput levels above a file system’s baseline level for periods of time. For more information, see Throughput scaling in Amazon EFS.

The Minimum statistic is the smallest burst credit balance for any minute during the period. The Maximum statistic is the largest burst credit balance for any minute during the period. The Average statistic is the average burst credit balance during the period.

Units: Bytes

Valid statistics: Minimum, Maximum, Average

ClientConnections

The number of client connections to a file system. When using a standard client, there is one connection per mounted Amazon EC2 instance.

Note

To calculate the average ClientConnections for periods greater than one minute, divide the Sum statistic by the number of minutes in the period.

Units: Count of client connections

Valid statistics: Sum

DataReadIOBytes

The number of bytes for each file system read operation.

The Sum statistic is the total number of bytes associated with read operations. The Minimum statistic is the size of the smallest read operation during the period. The Maximum statistic is the size of the largest read operation during the period. The Average statistic is the average size of read operations during the period. The SampleCount statistic provides a count of read operations.

Units:

  • Bytes for Minimum, Maximum, Average, and Sum.

  • Count for SampleCount.

Valid statistics: Minimum, Maximum, Average, Sum, SampleCount

DataWriteIOBytes

The number of bytes for each file write operation.

The Sum statistic is the total number of bytes associated with write operations. The Minimum statistic is the size of the smallest write operation during the period. The Maximum statistic is the size of the largest write operation during the period. The Average statistic is the average size of write operations during the period. The SampleCount statistic provides a count of write operations.

Units:

  • Bytes are the units for the Minimum, Maximum, Average, and Sum statistics.

  • Count for SampleCount.

Valid statistics: Minimum, Maximum, Average, Sum, SampleCount

MetadataIOBytes

The number of bytes for each metadata operation.

The Sum statistic is the total number of bytes associated with metadata operations. The Minimum statistic is the size of the smallest metadata operation during the period. The Maximum statistic is the size of the largest metadata operation during the period. The Average statistic is the size of the average metadata operation during the period. The SampleCount statistic provides a count of metadata operations.

Units:

  • Bytes are the units for the Minimum, Maximum, Average, and Sum statistics.

  • Count for SampleCount.

Valid statistics: Minimum, Maximum, Average, Sum, SampleCount

PercentIOLimit

Shows how close a file system is to reaching the I/O limit of the General Purpose performance mode. If this metric is at 100% more often than not, consider moving your application to a file system using the Max I/O performance mode.

Note

This metric is only submitted for file systems using the General Purpose performance mode.

Units:

  • Percent

PermittedThroughput

The maximum amount of throughput a file system is allowed, given the file system size and BurstCreditBalance. For more information, see Amazon EFS Performance.

The Minimum statistic is the smallest throughput permitted for any minute during the period. The Maximum statistic is the highest throughput permitted for any minute during the period. The Average statistic is the average throughput permitted during the period.

Units: Bytes per second

Valid statistics: Minimum, Maximum, Average

TotalIOBytes

The number of bytes for each file system operation, including data read, data write, and metadata operations.

The Sum statistic is the total number of bytes associated with all file system operations. The Minimum statistic is the size of the smallest operation during the period. The Maximum statistic is the size of the largest operation during the period. The Average statistic is the average size of an operation during the period. The SampleCount statistic provides a count of all operations.

Note

To calculate the average operations per second for a period, divide the SampleCount statistic by the number of seconds in the period. To calculate the average throughput (Bytes per second) for a period, divide the Sum statistic by the number of seconds in the period.

Units:

  • Bytes for Minimum, Maximum, Average, and Sum statistics.

  • Count for SampleCount.

Valid statistics: Minimum, Maximum, Average, Sum, SampleCount

Bytes Reported in CloudWatch

As with Amazon S3 and Amazon EBS, Amazon EFS CloudWatch metrics are reported as raw Bytes. Bytes are not rounded to either a decimal or binary multiple of the unit. Keep this in mind when calculating your burst rate using the data you get from the metrics. For more information on bursting, see Throughput Scaling in Amazon EFS.

Amazon EFS Dimensions

Amazon EFS metrics use the EFS namespace and provides metrics for a single dimension, FileSystemId. A file system's ID can be found in the Amazon EFS management console, and it takes the form of fs-XXXXXXXX.