Step Functions service quotas - Amazon Step Functions
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Step Functions service quotas

Amazon Step Functions provide default service quotas for state machine parameters, such as the number of API actions during a time period or the number of state machines that you can define. Quotas are designed to prevent misconfigured state machine from consuming all of the resources of the system, although many do not have hard limits.

To request a service quota increase, you can do one of the following:

  • Use the Service Quotas console at https://console.amazonaws.cn/servicequotas/home. For information about requesting a quota increase using the Service Quotas console, see Requesting a quota increase in the Service Quotas User Guide.

  • Use the Support Center page in the Amazon Web Services Management Console to request a quota increase for resources provided by Amazon Step Functions on a per-Region basis. For more information, see Amazon service quotas in the Amazon Web Services General Reference.

Note

If a particular stage of your state machine execution or activity execution takes too long, you can configure a state machine timeout to cause a timeout event.

General quotas

Names of state machines, executions, and activity tasks must not exceed 80 characters in length. These names must be unique for your account and Amazon Region, and must not contain any of the following:

  • Whitespace

  • Wildcard characters (? *)

  • Bracket characters (< > { } [ ])

  • Special characters (" # % \ ^ | ~ ` $ & , ; : /)

  • Control characters (\\u0000 - \\u001f or \\u007f - \\u009f).

Step Functions accepts names for state machines, executions, activities, and labels that contain non-ASCII characters. Because such characters will not work with Amazon CloudWatch, we recommend using only ASCII characters so you can track metrics in CloudWatch.

Quotas related to accounts

Resource Default quota Can be increased to
Maximum number of registered state machines 10,000 25,000

Maximum number of registered activities

10,000 15,000

Maximum size of state machine definition

1 MB Hard quota
Maximum request size 1 MB per request. This is the total data size per Step Functions API request, including the request header and all other associated request data. Hard quota

Maximum open executions per account

1,000,000 executions for each Amazon Web Services account in each Amazon Web Services Region. Exceeding this limit will cause an ExecutionLimitExceeded error. This doesn't apply to Express Workflows. Millions

Maximum number of open Map Runs

1000

This quota applies to Distributed Map state.

An open Map Run is a Map Run that has started, but hasn't yet completed. Scheduled Map Runs wait at the MapRunStarted event until the total number of open Map Runs is less than the quota.

Hard quota

Maximum redrives of a Map Run.

1000

This quota applies to Distributed Map state.

Hard quota
Maximum number of parallel Map Run child executions 10,000

Hard quota

Quotas related to HTTP Task

HTTP Tasks are throttled using a token bucket scheme to maintain the Step Functions service bandwidth.

Resource Bucket size Refill rate per second
HTTP Task 300 300
Resource Default quota
HTTP Task duration — time to send an HTTP request and receive a response 60 seconds (Hard quota)

Quotas related to state throttling

Step Functions state transitions are throttled using a token bucket scheme to maintain service bandwidth. Standard Workflows and Express Workflows have different state transition throttling. Standard Workflows quotas are soft quotas and can be increased.

Note

Throttling on the StateTransition service metric is reported as ExecutionThrottled in Amazon CloudWatch. For more information, see the ExecutionThrottled CloudWatch metric.

Standard Express
Service metric Bucket size Refill rate per second Bucket size Refill rate per second

StateTransition US East (N. Virginia), US West (Oregon), and Europe (Ireland)

5,000 5,000

Unlimited

Unlimited

StateTransitionAll other regions

800 800

Unlimited

Unlimited

Quotas related to API action throttling

Some Step Functions API actions are throttled using a token bucket scheme to maintain service bandwidth. The following are soft quotas and can be increased.

Note

Throttling quotas are per account, per Amazon Region.

Amazon Step Functions may increase both the bucket size and refill rate at any time.

Standard Express
API name Bucket size Refill rate per second Bucket size Refill rate per second
StartExecutionUS East (N. Virginia), US West (Oregon), and Europe (Ireland) 1,300 300 6,000 6,000
StartExecutionAll other regions 800 150 6,000 6,000

Quota related to TestState API

API name Quota Can be increased to
TestState 1 transaction per second (TPS) Hard quota

Other quotas

The following are soft quotas and can be increased.

US East (N. Virginia), US West (Oregon), and Europe (Ireland) All other regions
API name Bucket size Refill rate per second Bucket size Refill rate per second
CreateActivity 100 1 100 1
CreateStateMachine 100 1 100 1
CreateStateMachineAlias 100 1 100 1
DeleteActivity 100 1 100 1
DeleteStateMachine 100 1 100 1
DeleteStateMachineAlias 100 1 100 1
DeleteStateMachineVersion 100 1 100 1
DescribeActivity 200 1 200 1
DescribeExecution 300 15 250 10
DescribeMapRun 200 1 200 1
DescribeStateMachine 200 20 200 20
DescribeStateMachineAlias 200 1 200 1
DescribeStateMachineForExecution 200 1 200 1
GetActivityTask 3,000 500 1,500 300
GetExecutionHistory 400 20 400 20
ListActivities 100 10 100 5
ListExecutions 200 5 100 2
ListMapRuns 100 1 100 1
ListStateMachineAliases 100 1 100 1
ListStateMachines 100 5 100 5
ListStateMachineVersions 100 1 100 1
ListTagsForResource 100 1 100 1
PublishStateMachineVersion 100 1 100 1
RedriveExecution 1,300 300 800 150
SendTaskFailure 3,000 500 1,500 300
SendTaskHeartbeat 3,000 500 1,500 300
SendTaskSuccess 3,000 500 1,500 300
StartSyncExecution

Synchronous Express execution API calls don't contribute to existing account capacity limits. Step Functions provides capacity on demand and automatically scales with sustained workload. Surges in workload may be throttled until capacity is available.

If you experience throttling, try again after some time. For information about Synchronous Express workflows, see Synchronous and Asynchronous Express Workflows in Step Functions.

StopExecution 1,000 200 500 25
TagResource 200 1 200 1
UntagResource 200 1 200 1
UpdateMapRun 100 1 100 1
UpdateStateMachine 100 1 100 1
UpdateStateMachineAlias 100 1 100 1
ValidateStateMachineDefinition 100 1 100 1

Quotas related to state machine executions

The following table describes quotas related to state machine executions. State machine execution quotas are hard quotas that can't be changed, except for the Execution history retention time quota.

Quota Standard Express

Maximum execution time

1 year. If an execution runs for more than the 1-year maximum, it will fail with a States.Timeout error and emit a ExecutionsTimedOut CloudWatch metric.

5 minutes. If an execution runs for more than the 5-minute maximum, it will fail with a States.Timeout error and emit a ExecutionsTimedOut CloudWatch metric.

Maximum execution history size

25,000 events in a single state machine execution history. If the execution history reaches this quota, the execution will fail. To avoid this, see Starting new executions to avoid reaching the history quota in Step Functions. Unlimited.

Maximum execution idle time

1 year

Constrained by maximum execution time.

5 minutes

Constrained by maximum execution time.

Execution history retention time

90 days after an execution is closed. After this time, you can no longer retrieve or view the execution history. There is no further quota for the number of closed executions that Step Functions retains.

To meet compliance, organizational, or regulatory requirements, you can reduce the execution history retention period to 30 days by sending a quota request. To do this, use the Amazon Support Center Console and create a new case.

The change to reduce the retention period to 30 days is applicable for each account in a Region.

To see execution history, Amazon CloudWatch Logs logging must be configured. For more information, see Using CloudWatch Logs to log execution history in Step Functions.

Execution redrivable period

14 days

Hard quota applies to Distributed Map state.

Redrivable period refers to the time during which you can redrive a given Standard Workflow execution. This period starts from the day a state machine completes its execution.

Redrive is not supported for Express workflows.

Quotas related to task executions

The following table describes quotas related to task executions. These are all hard quotas that cannot be changed.

Quota Standard Express
Maximum task execution time 1 year — Constrained by maximum execution time. 5 minutes — Constrained by maximum execution time.
Maximum time Step Functions keeps a task in the queue 1 year — Constrained by maximum execution time. 5 minutes — Constrained by maximum execution time.
Maximum activity pollers per Amazon Resource Name (ARN) 1,000 pollers calling GetActivityTask per ARN. Exceeding this quota results in this error: "The maximum number of workers concurrently polling for activity tasks has been reached." Does not apply to Express Workflows.
Maximum input or output size for a task, state, or execution 256 KiB of data as a UTF-8 encoded string. This quota affects tasks (activity, Lambda function, or integrated service), state or execution output, and input data when scheduling a task, entering a state, or starting an execution. 256 KiB of data as a UTF-8 encoded string. This quota affects tasks (activity, Lambda function, or integrated service), state or execution output, and input data when scheduling a task, entering a state, or starting an execution.

Quotas related to versions and aliases

Resource Default quota
Maximum number of published state machine versions 1000 per state machine
Maximum number of state machine aliases 100 per state machine

To request an increase to soft limits for published state machine versions and aliases, use the Support Center page in the Amazon Web Services Management Console.

Restrictions related to tagging

The following tagging restrictions can not be modified or increased.

  • Prefix restriction — Do not use the aws: prefix in your tag names or values because it is reserved for Amazon use only. You cannot edit or delete tag names or values with an aws: prefix. Tags with the aws: prefix do not count against your tags per resource quota.

  • Character restrictions — Tags may only contain Unicode letters, digits, whitespace, or the following symbols: _ . : / = + - @

Restriction Description
Maximum number of tags per resource 50
Maximum key length 128 Unicode characters in UTF-8
Maximum value length 256 Unicode characters in UTF-8