Monitoring Step Functions metrics using Amazon CloudWatch
Monitoring is an important part of maintaining the reliability, availability, and performance of AWS Step Functions and your AWS solutions. You should collect as much monitoring data from the AWS services that you use so that you can debug multi-point failures.
Before you start monitoring Step Functions, you should create a monitoring plan that answers the following questions:
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What are your monitoring goals?
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What resources will you monitor?
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How often will you monitor these resources?
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What monitoring tools will you use?
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Who will perform the monitoring tasks?
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Who should be notified when something goes wrong?
The next step is to establish a baseline for normal performance in your environment. To do this, measure performance at various times and under different load conditions. As you monitor Step Functions, consider storing historical monitoring data. Such data can give you a baseline to compare against current performance data, to identify normal performance patterns and performance anomalies, and to devise ways to address issues.
For example, with Step Functions, you can monitor how many activities or AWS Lambda tasks fail due to a heartbeat timeout. When performance falls outside your established baseline, you might have to change your heartbeat interval.
To establish a baseline you should, at a minimum, monitor the following metrics:
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ActivitiesStarted -
ActivitiesTimedOut -
ExecutionsStarted -
ExecutionsTimedOut -
LambdaFunctionsStarted -
LambdaFunctionsTimedOut
Step Functions metrics for CloudWatch
Step Functions provides the following types of metrics to Amazon CloudWatch. You can use these metrics to track your state machines and activities and to set alarms on threshold values. You can view metrics using the AWS Management Console.
CloudWatch metrics delivery
CloudWatch metrics are delivered on a best-effort basis.
The completeness and timeliness of metrics are not guaranteed. The data point for a particular request might be returned with a timestamp that is later than when the request was actually processed. The data point for a minute might be delayed before being available through CloudWatch, or it might not be delivered at all. CloudWatch request metrics give you an idea of the state machine executions in near-real time. It is not meant to be a complete accounting of all execution-related metrics.
It follows from the best-effort nature of this feature that the reports available
at the Billing & Cost
Management Dashboard
Metrics that report a time interval
Some of the Step Functions CloudWatch metrics are time intervals, always measured in milliseconds. These metrics generally correspond to stages of your execution for which you can set state machine, activity, and Lambda function timeouts, with descriptive names.
For example, the ActivityRunTime metric measures the time it takes for an
activity to complete after it begins to execute. You can set a timeout value for the
same time period.
In the CloudWatch console, you can get the best results if you choose average as the display statistic for time interval metrics.
Metrics that report a count
Some of the Step Functions CloudWatch metrics report results as a count. For
example, ExecutionsFailed records the number of failed state machine
executions.
Step Functions emits two ExecutionsStarted metrics for every state machine execution. This causes the SampleCount statistic for the ExecutionsStarted metric to show the value of 2 for every state machine execution. The SampleCount statistic shows ExecutionStarted=1 and ExecutionStarted=0 when the execution completes.
Tip
We recommend selecting Sum as the display statistic for metrics that report a count in the CloudWatch console.
Execution metrics
The AWS/States namespace includes the following metrics for all Step Functions
executions. These are dimensionless metrics that apply across your account in a region.
| Metric | Description |
|---|---|
OpenExecutionCount |
Approximate number of currently open executions—workflows that are currently in progress in your account. The intent is to provide insight into when your workflows are approaching the maximum execution limit, to avoid ExecutionLimitExceeded errors when calling
|
OpenExecutionLimit |
Maximum number of open executions. For more information, see Quotas related to accounts. This limit does not apply to Express Workflows. |
Execution metrics for state machine with version or alias
When you run a state machine execution with a version or an alias, Step Functions emits the following metrics. The ExecutionThrottled metric will only be emitted in the case of throttled execution. These metrics will include a StateMachineArn to identify a specific state machine.
| Metric | Description |
|---|---|
ExecutionTime |
Interval, in milliseconds, between the time the execution starts and the time it closes. |
ExecutionThrottled |
Number of StateEntered events and retries that
have been throttled. This is related to StateTransition
throttling. For more information, see Quotas related to state
throttling. |
ExecutionsAborted |
Number of aborted or terminated executions. |
ExecutionsFailed |
Number of failed executions. |
ExecutionsStarted |
Number of started executions. |
ExecutionsSucceeded |
Number of successfully completed executions. |
ExecutionsTimedOut |
Number of executions that time out for any reason. |
Execution metrics for Express Workflows
The AWS/States namespace includes the following metrics for Step Functions Express Workflows' executions.
| Metric | Description |
|---|---|
ExpressExecutionMemory
|
The total memory consumed by an Express Workflow. |
ExpressExecutionBilledDuration |
The duration for which an Express Workflow is charged. |
ExpressExecutionBilledMemory |
The amount of consumed memory for which an Express Workflow is charged. |
Redrive execution metrics for Standard Workflows
When you redrive a state machine execution, Step Functions emits the following metrics.
For all redriven executions, the Executions* metric is emitted. For example, say a redriven execution aborts. This execution will emit non-zero datapoints for both RedrivenExecutionsAborted and ExecutionsAborted.
| Metric | Description |
|---|---|
ExecutionsRedriven |
Number of redriven executions. |
RedrivenExecutionsAborted |
Number of redriven executions that are canceled or terminated. |
RedrivenExecutionsTimedOut |
Number of redriven executions that time out for any reason. |
RedrivenExecutionsSucceeded |
Number of redriven executions that completed successfully. |
RedrivenExecutionsFailed |
Number of redriven executions that failed. |
Dimension for Step Functions execution metrics
| Dimension | Description |
|---|---|
StateMachineArn
|
The Amazon Resource Name (ARN) of the state machine for the execution in question. |
Dimensions for executions with version
| Dimension | Description |
|---|---|
StateMachineArn
|
The Amazon Resource Name (ARN) of the state machine whose execution was started by a version. |
Version |
State machine version used to start the execution. |
Dimensions for executions with an alias
| Dimension | Description |
|---|---|
StateMachineArn
|
The Amazon Resource Name (ARN) of the state machine whose execution was started by an alias. |
Alias |
State machine alias used to start the execution. |
Resource count metrics for versions and aliases
The AWS/States namespace includes the following metrics for the count of versions and aliases of a state machine.
Dimension for resource count metrics for versions and aliases
| Dimension | Description |
|---|---|
ResourceArn
|
The Amazon Resource Name (ARN) of the state machine with a version or an alias. |
Activity Metrics
The AWS/States namespace includes the following metrics for Step Functions
activities.
| Metric | Description |
|---|---|
ActivityRunTime
|
Interval, in milliseconds, between the time the activity starts and the time it closes. |
ActivityScheduleTime |
Interval, in milliseconds, for which the activity stays in the schedule state. |
ActivityTime |
Interval, in milliseconds, between the time the activity is scheduled and the time it closes. |
ActivitiesFailed |
Number of failed activities. |
ActivitiesHeartbeatTimedOut |
Number of activities that time out due to a heartbeat timeout. |
ActivitiesScheduled |
Number of scheduled activities. |
ActivitiesStarted |
Number of started activities. |
ActivitiesSucceeded |
Number of successfully completed activities. |
ActivitiesTimedOut |
Number of activities that time out on close. |
Dimension for Step Functions Activity Metrics
| Dimension | Description |
|---|---|
|
|
The ARN of the activity. |
Lambda Function Metrics
The AWS/States namespace includes the following metrics for Step Functions
Lambda functions.
| Metric | Description |
|---|---|
LambdaFunctionRunTime |
Interval, in milliseconds, between the time the Lambda function starts and the time it closes. |
LambdaFunctionScheduleTime |
Interval, in milliseconds, for which the Lambda function stays in the schedule state. |
LambdaFunctionTime |
Interval, in milliseconds, between the time the Lambda function is scheduled and the time it closes. |
LambdaFunctionsFailed |
Number of failed Lambda functions. |
LambdaFunctionsScheduled |
Number of scheduled Lambda functions. |
LambdaFunctionsStarted |
Number of started Lambda functions. |
LambdaFunctionsSucceeded |
Number of successfully completed Lambda functions. |
LambdaFunctionsTimedOut |
Number of Lambda functions that time out on close. |
Dimension for Step Functions Lambda Function Metrics
| Dimension | Description |
|---|---|
|
|
The ARN of the Lambda function. |
Note
Lambda Function Metrics are emitted for Task states that specify the Lambda function ARN in the
Resource field. Task states that use "Resource": "arn:aws:states:::lambda:invoke"
emit Service Integration Metrics instead. For more information, see Invoke an AWS Lambda function with Step Functions.
Service Integration Metrics
The AWS/States namespace includes the following metrics for Step Functions
service integrations. For more information, see Integrating services with Step Functions.
| Metric | Description |
|---|---|
ServiceIntegrationRunTime |
Interval, in milliseconds, between the time the Service Task starts and the time it closes. |
ServiceIntegrationScheduleTime |
Interval, in milliseconds, for which the Service Task stays in the schedule state. |
ServiceIntegrationTime |
Interval, in milliseconds, between the time the Service Task is scheduled and the time it closes. |
ServiceIntegrationsFailed |
Number of failed Service Tasks. |
ServiceIntegrationsScheduled |
Number of scheduled Service Tasks. |
ServiceIntegrationsStarted |
Number of started Service Tasks. |
ServiceIntegrationsSucceeded |
Number of successfully completed Service Tasks. |
ServiceIntegrationsTimedOut |
Number of Service Tasks that time out on close. |
Dimension for Step Functions Service Integration Metrics
| Dimension | Description |
|---|---|
|
|
The resource ARN of the integrated service. |
Service Metrics
The AWS/States namespace includes the following metrics for the Step Functions
service.
| Metric | Description |
|---|---|
ThrottledEvents
|
Count of requests that have been throttled. |
ProvisionedBucketSize |
Count of available requests per second. |
ProvisionedRefillRate |
Count of requests per second that are allowed into the bucket. |
ConsumedCapacity |
Count of requests per second. |
Dimension for Step Functions Service Metrics
| Dimension | Description |
|---|---|
|
|
Filters data to show State Transitions metrics. |
API Metrics
The AWS/States namespace includes the following metrics for the Step Functions
API.
| Metric | Description |
|---|---|
ThrottledEvents
|
Count of requests that have been throttled. |
ProvisionedBucketSize |
Count of available requests per second. |
ProvisionedRefillRate |
Count of requests per second that are allowed into the bucket. |
ConsumedCapacity |
Count of requests per second. |
Dimension for Step Functions API Metrics
| Dimension | Description |
|---|---|
|
|
Filters data to an API of the specified API name. |
Viewing Step Functions metrics in CloudWatch
You can use the CloudWatch console to view Step Functions metrics for executions, activities, functions, and service integrations.
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Sign in to the AWS Management Console and open the CloudWatch console.
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Choose Metrics, and on the All Metrics tab, choose States.
If you ran any executions recently, you will see up to four types of metrics:
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Execution Metrics
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Activity Function Metrics
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Lambda Function Metrics
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Service Integration Metrics
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Choose a metric type to see a list of metrics.
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To sort your metrics by Metric Name or StateMachineArn, use the column headings.
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To view graphs for a metric, choose the box next to the metric on the list. You can change the graph parameters using the time range controls above the graph view.
You can choose custom time ranges using relative or absolute values (specific days and times). You can also use the dropdown list to display values as lines, stacked areas, or numbers (values).
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To view the details about a graph, hover over the metric color code that appears below the graph to display the metric details.
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For more information about working with CloudWatch metrics, see Using Amazon CloudWatch Metrics in the Amazon CloudWatch User Guide.
Setting alarms for Step Functions metrics in CloudWatch
You can use Amazon CloudWatch alarms to perform actions. For example, if you want to know when
an alarm threshold is reached, you can set an alarm to send a notification to an Amazon SNS
topic or to send an email when the StateMachinesFailed metric rises above a
certain threshold.
To set an alarm on a metric
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Sign in to the AWS Management Console and open the CloudWatch console.
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Choose Metrics, and on the All Metrics tab, choose States.
If you ran any executions recently, you will see up to four types of metrics:
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Execution Metrics
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Activity Function Metrics
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Lambda Function Metrics
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Service Integration Metrics
-
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Choose a metric type to see a list of metrics.
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Choose a metric, and then choose Graphed metrics.
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Choose the bell-shaped icon next to a metric on the list to display the Create Alarm page.
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Enter the values for the Alarm threshold and Actions, and then choose Create Alarm.
For more information about setting and using CloudWatch alarms, see Creating Amazon CloudWatch Alarms in the Amazon CloudWatch User Guide.
