Amazon CloudWatch metrics for Amazon EFS
Amazon EFS metrics use the EFS
namespace and provide metrics for a single
dimension, FileSystemId
. A file system's ID can be found in the Amazon EFS
console, and it takes the form of fsabcdef0123456789a
.
The AWS/EFS
namespace includes the following metrics.
TimeSinceLastSync

Shows the amount of time that has passed since the last successful sync to the destination file system in a replication configuration. Any changes to data on the source file system that occurred before the
TimeSinceLastSync
value have been successfully replicated. Any changes on the source that occurred afterTimeSinceLastSync
might not be fully replicated. For more information, see Amazon EFS replication.Units: Seconds
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 percent 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
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 systemâ€™s baseline level for periods of time. For more information, see Bursting Throughput mode.
The
Minimum
statistic is the smallest burst credit balance for any minute during the period. TheMaximum
statistic is the largest burst credit balance for any minute during the period. TheAverage
statistic is the average burst credit balance during the period.Units: Bytes
Valid statistics:
Minimum
,Maximum
,Average
PermittedThroughput

The maximum amount of throughput that a file system can drive.

For file systems in Bursting Throughput mode, this value is a function of the file system size and
BurstCreditBalance
. 
For file systems in Elastic Throughput mode, this value reflects the maximum write throughput of the file system.

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 more information, see Amazon EFS performance.
The
Minimum
statistic is the smallest throughput permitted for any minute during the period. TheMaximum
statistic is the highest throughput permitted for any minute during the period. TheAverage
statistic is the average throughput permitted during the period.Note Read operations are metered at onethird the rate of other operations.
Units: Bytes per second
Valid statistics:
Minimum
,Maximum
,Average

MeteredIOBytes

The number of metered bytes for each file system operation, including data read, data write, and metadata operations, with read operations metered at onethird the rate of other operations.
You can create a CloudWatch metric math expression that compares
MeteredIOBytes
toPermittedThroughput
. If these values are equal, then you are consuming the entire amount of throughput allocated to your file system. In this situation, you might consider changing the file system's throughput mode to get higher throughput.The
Sum
statistic is the total number of metered bytes associated with all file system operations. TheMinimum
statistic is the size of the smallest operation during the period. TheMaximum
statistic is the size of the largest operation during the period. TheAverage
statistic is the average size of an operation during the period. TheSampleCount
statistic provides a count of all operations.Units:

Bytes for
Minimum
,Maximum
,Average
, andSum
statistics. 
Count for
SampleCount
.
Valid statistics:
Minimum
,Maximum
,Average
,Sum
,SampleCount

TotalIOBytes

The actual number of bytes for each file system operation, including data read, data write, and metadata operations. This is the actual amount that your application is driving, and not the throughput the file system is being metered at. It might be higher than the numbers shown in
PermittedThroughput
.The
Sum
statistic is the total number of bytes associated with all file system operations. TheMinimum
statistic is the size of the smallest operation during the period. TheMaximum
statistic is the size of the largest operation during the period. TheAverage
statistic is the average size of an operation during the period. TheSampleCount
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 theSum
statistic by the number of seconds in the period.Units:

Bytes for
Minimum
,Maximum
,Average
, andSum
statistics. 
Count for
SampleCount
.
Valid statistics:
Minimum
,Maximum
,Average
,Sum
,SampleCount

DataReadIOBytes

The number of bytes for each file system read operation.
The
Sum
statistic is the total number of bytes associated with read operations. TheMinimum
statistic is the size of the smallest read operation during the period. TheMaximum
statistic is the size of the largest read operation during the period. TheAverage
statistic is the average size of read operations during the period. TheSampleCount
statistic provides a count of read operations.Units:

Bytes for
Minimum
,Maximum
,Average
, andSum
. 
Count for
SampleCount
.
Valid statistics:
Minimum
,Maximum
,Average
,Sum
,SampleCount

DataWriteIOBytes

The number of bytes for each file system write operation.
The
Sum
statistic is the total number of bytes associated with write operations. TheMinimum
statistic is the size of the smallest write operation during the period. TheMaximum
statistic is the size of the largest write operation during the period. TheAverage
statistic is the average size of write operations during the period. TheSampleCount
statistic provides a count of write operations.Units:

Bytes are the units for the
Minimum
,Maximum
,Average
, andSum
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. TheMinimum
statistic is the size of the smallest metadata operation during the period. TheMaximum
statistic is the size of the largest metadata operation during the period. TheAverage
statistic is the size of the average metadata operation during the period. TheSampleCount
statistic provides a count of metadata operations.Units:

Bytes are the units for the
Minimum
,Maximum
,Average
, andSum
statistics. 
Count for
SampleCount
.
Valid statistics:
Minimum
,Maximum
,Average
,Sum
,SampleCount

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 theSum
statistic by the number of minutes in the period.Units: Count of client connections
Valid statistics:
Sum
StorageBytes

The size of the file system in bytes, including the amount of data stored in the EFS Standard and EFS Standardâ€“Infrequent Access (EFS StandardIA) storage classes. This metric is emitted every 15 minutes to CloudWatch. For more information about storage classes, see EFS storage classes.
The
StorageBytes
metric has three dimensions:
Total
is the latest known metered size (in bytes) of data stored in the file system, including both storage classes. 
Standard
is the latest known metered size (in bytes) of data stored in the EFS Standard storage class. 
IA
is the latest known metered size (in bytes) of data stored in the EFS StandardIA storage class.
Units: Bytes
Note StorageBytes
is displayed on the Amazon EFS console File system metrics page using base 1024 units (kibibytes, mebibytes, gibibytes, and tebibytes). 
Bytes reported in CloudWatch
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 about bursting, see Bursting Throughput mode.