Metrics analyzed by AWS Compute Optimizer
After you opt in, AWS Compute Optimizer begins analyzing the specifications (vCPUs, memory, storage, and so on) and the CloudWatch metrics of your running resources from a period of the last 14 days or longer if you activate the enhanced infrastructure metrics recommendation preference. Compute Optimizer requires at least 30 consecutive hours of metrics data from your resource to generate recommendations. After the analysis is complete, which can take up to 12 hours, Compute Optimizer presents its findings on the dashboard page. For more information, see Viewing the AWS Compute Optimizer dashboard.
EC2 instance metrics
Compute Optimizer analyzes the following CloudWatch metrics of your EC2 instances, including instances that are part of Auto Scaling groups.
| Metric | Description |
|---|---|
CPUutilization
|
The percentage of allocated EC2 compute units that are in use on the instance. This metric identifies the processing power required to run an application on an instance. |
|
Memory utilization |
The amount of memory that has been used in some way during the sample period. This metric identifies the memory required to run an application on an instance. Memory utilization is analyzed only for resources that have the unified CloudWatch agent installed on them. For more information, see Enabling memory utilization with the CloudWatch Agent. |
NetworkIn
|
The number of bytes received on all network interfaces by the instance. This metric identifies the volume of incoming network traffic to an instance. |
NetworkOut
|
The number of bytes sent out on all network interfaces by the instance. This metric identifies the volume of outgoing network traffic from an instance. |
NetworkPacketsIn
|
The number of packets received by the instance. |
NetworkPacketsOut
|
The number of packets sent out by the instance. |
DiskReadOps
|
The read operations per second of the instance store volume of the instance. |
DiskWriteOps
|
The write operations per second of the instance store volume of the instance. |
DiskReadBytes
|
The read bytes per second of the instance store volume of the instance. |
DiskWriteBytes
|
The write bytes per second of the instance store volume of the instance. |
VolumeReadBytes
|
The read bytes per second of EBS volumes attached to the instance. Displayed as KiB/seconds in the console. |
VolumeWriteBytes
|
The write bytes per second of EBS volumes attached to the instance. Displayed as KiB/seconds in the console. |
VolumeReadOps
|
The read operations per second of EBS volumes attached to the instance. |
VolumeWriteOps
|
The write operations per second of EBS volumes attached to the instance. |
For more information about instance metrics, see List the available CloudWatch metrics for your instances in the Amazon Elastic Compute Cloud User Guide. For more information about EBS volume metrics, see Amazon CloudWatch metrics for Amazon EBS in the Amazon Elastic Compute Cloud User Guide.
Enabling memory utilization with the CloudWatch Agent
Install the CloudWatch agent on your instances to have Compute Optimizer analyze the memory utilization of your instances. Enabling Compute Optimizer to analyze memory utilization data for your instances provides an additional measurement of data that further improves the recommendations provided by the service. For more information about installing the CloudWatch agent, see Collecting Metrics and Logs from Amazon EC2 Instances and On-Premises Servers with the CloudWatch Agent in the Amazon CloudWatch User Guide.
On Linux instances, Compute Optimizer analyses the mem_used_percent metric in the
CWAgent namespace, or the legacy MemoryUtilization metric in the
System/Linux namespace. On Windows instances, Compute Optimizer analyses the Memory
% Committed Bytes In Use metric in the CWAgent namespace.
Additionally, the namespace must contain the InstanceId dimension. Compute Optimizer will
not be able to collect memory utilization data for your instance if the
InstanceId dimension is missing, or if you overwrite it with your own custom
dimension name. Namespaces and dimensions are defined in the CloudWatch Agent configuration file.
For more information, see Create the CloudWatch Agent
Configuration File in the Amazon CloudWatch User Guide.
EBS volume metrics
Compute Optimizer analyzes the following CloudWatch metrics of your EBS volumes.
| Metric | Description |
|---|---|
VolumeReadBytes
|
The read bytes per second of the EBS volume. |
VolumeWriteBytes
|
The write bytes per second of the EBS volume. |
VolumeReadOps
|
The read operations per second of the EBS volume. |
VolumeWriteOps
|
The write operations per second of the EBS volume. |
For more information about these metrics, see Amazon CloudWatch metrics for Amazon EBS in the Amazon Elastic Compute Cloud User Guide.
Lambda function metrics
Compute Optimizer analyzes the following CloudWatch metrics of your Lambda functions.
| Metric | Description |
|---|---|
Invocations
|
The number of times your function code is executed, including successful executions and executions that result in a function error. |
Duration
|
The amount of time that your function code spends processing an event. |
Errors
|
The number of invocations that result in a function error. Function errors include exceptions thrown by your code and exceptions thrown by the Lambda runtime. The runtime returns errors for issues such as timeouts and configuration errors. |
Throttles
|
The number of invocation requests that are throttled. |
For more information about these metrics, see Working with AWS Lambda function metrics in the AWS Lambda Developer Guide.
In addition to these metrics, Compute Optimizer analyzes the memory utilization of
your function during the look-back period. For more information about memory utilization for
Lambda functions, see Understanding AWS Lambda behavior using Amazon CloudWatch Logs Insights
