StartWorkflowExecution
Starts an execution of the workflow type in the specified domain using the provided
workflowId
and input data.
This action returns the newly started workflow execution.
Access Control
You can use IAM policies to control this action's access to Amazon SWF resources as follows:
-
Use a
Resource
element with the domain name to limit the action to only specified domains. -
Use an
Action
element to allow or deny permission to call this action. -
Constrain the following parameters by using a
Condition
element with the appropriate keys.-
tagList.member.0
: The key isswf:tagList.member.0
. -
tagList.member.1
: The key isswf:tagList.member.1
. -
tagList.member.2
: The key isswf:tagList.member.2
. -
tagList.member.3
: The key isswf:tagList.member.3
. -
tagList.member.4
: The key isswf:tagList.member.4
. -
taskList
: String constraint. The key isswf:taskList.name
. -
workflowType.name
: String constraint. The key isswf:workflowType.name
. -
workflowType.version
: String constraint. The key isswf:workflowType.version
.
-
If the caller doesn't have sufficient permissions to invoke the action, or the
parameter values fall outside the specified constraints, the action fails. The associated
event attribute's cause
parameter is set to OPERATION_NOT_PERMITTED
.
For details and example IAM policies, see Using IAM to Manage Access to Amazon SWF
Workflows in the Amazon SWF Developer Guide.
Request Syntax
{
"childPolicy": "string
",
"domain": "string
",
"executionStartToCloseTimeout": "string
",
"input": "string
",
"lambdaRole": "string
",
"tagList": [ "string
" ],
"taskList": {
"name": "string
"
},
"taskPriority": "string
",
"taskStartToCloseTimeout": "string
",
"workflowId": "string
",
"workflowType": {
"name": "string
",
"version": "string
"
}
}
Request Parameters
For information about the parameters that are common to all actions, see Common Parameters.
The request accepts the following data in JSON format.
- childPolicy
-
If set, specifies the policy to use for the child workflow executions of this workflow execution if it is terminated, by calling the TerminateWorkflowExecution action explicitly or due to an expired timeout. This policy overrides the default child policy specified when registering the workflow type using RegisterWorkflowType.
The supported child policies are:
-
TERMINATE
– The child executions are terminated. -
REQUEST_CANCEL
– A request to cancel is attempted for each child execution by recording aWorkflowExecutionCancelRequested
event in its history. It is up to the decider to take appropriate actions when it receives an execution history with this event. -
ABANDON
– No action is taken. The child executions continue to run.
Note
A child policy for this workflow execution must be specified either as a default for the workflow type or through this parameter. If neither this parameter is set nor a default child policy was specified at registration time then a fault is returned.
Type: String
Valid Values:
TERMINATE | REQUEST_CANCEL | ABANDON
Required: No
-
- domain
-
The name of the domain in which the workflow execution is created.
The specified string must not contain a
:
(colon),/
(slash),|
(vertical bar), or any control characters (\u0000-\u001f
|\u007f-\u009f
). Also, it must not be the literal stringarn
.Type: String
Length Constraints: Minimum length of 1. Maximum length of 256.
Required: Yes
- executionStartToCloseTimeout
-
The total duration for this workflow execution. This overrides the defaultExecutionStartToCloseTimeout specified when registering the workflow type.
The duration is specified in seconds; an integer greater than or equal to
0
. Exceeding this limit causes the workflow execution to time out. Unlike some of the other timeout parameters in Amazon SWF, you cannot specify a value of "NONE" for this timeout; there is a one-year max limit on the time that a workflow execution can run.Note
An execution start-to-close timeout must be specified either through this parameter or as a default when the workflow type is registered. If neither this parameter nor a default execution start-to-close timeout is specified, a fault is returned.
Type: String
Length Constraints: Maximum length of 8.
Required: No
- input
-
The input for the workflow execution. This is a free form string which should be meaningful to the workflow you are starting. This
input
is made available to the new workflow execution in theWorkflowExecutionStarted
history event.Type: String
Length Constraints: Maximum length of 32768.
Required: No
- lambdaRole
-
The IAM role to attach to this workflow execution.
Note
Executions of this workflow type need IAM roles to invoke Lambda functions. If you don't attach an IAM role, any attempt to schedule a Lambda task fails. This results in a
ScheduleLambdaFunctionFailed
history event. For more information, see https://docs.aws.amazon.com/amazonswf/latest/developerguide/lambda-task.html in the Amazon SWF Developer Guide.Type: String
Length Constraints: Minimum length of 1. Maximum length of 1600.
Required: No
- tagList
-
The list of tags to associate with the workflow execution. You can specify a maximum of 5 tags. You can list workflow executions with a specific tag by calling ListOpenWorkflowExecutions or ListClosedWorkflowExecutions and specifying a TagFilter.
Type: Array of strings
Array Members: Maximum number of 5 items.
Length Constraints: Minimum length of 0. Maximum length of 256.
Required: No
- taskList
-
The task list to use for the decision tasks generated for this workflow execution. This overrides the
defaultTaskList
specified when registering the workflow type.Note
A task list for this workflow execution must be specified either as a default for the workflow type or through this parameter. If neither this parameter is set nor a default task list was specified at registration time then a fault is returned.
The specified string must not contain a
:
(colon),/
(slash),|
(vertical bar), or any control characters (\u0000-\u001f
|\u007f-\u009f
). Also, it must not be the literal stringarn
.Type: TaskList object
Required: No
- taskPriority
-
The task priority to use for this workflow execution. This overrides any default priority that was assigned when the workflow type was registered. If not set, then the default task priority for the workflow type is used. Valid values are integers that range from Java's
Integer.MIN_VALUE
(-2147483648) toInteger.MAX_VALUE
(2147483647). Higher numbers indicate higher priority.For more information about setting task priority, see Setting Task Priority in the Amazon SWF Developer Guide.
Type: String
Required: No
- taskStartToCloseTimeout
-
Specifies the maximum duration of decision tasks for this workflow execution. This parameter overrides the
defaultTaskStartToCloseTimout
specified when registering the workflow type using RegisterWorkflowType.The duration is specified in seconds, an integer greater than or equal to
0
. You can useNONE
to specify unlimited duration.Note
A task start-to-close timeout for this workflow execution must be specified either as a default for the workflow type or through this parameter. If neither this parameter is set nor a default task start-to-close timeout was specified at registration time then a fault is returned.
Type: String
Length Constraints: Maximum length of 8.
Required: No
- workflowId
-
The user defined identifier associated with the workflow execution. You can use this to associate a custom identifier with the workflow execution. You may specify the same identifier if a workflow execution is logically a restart of a previous execution. You cannot have two open workflow executions with the same
workflowId
at the same time within the same domain.The specified string must not contain a
:
(colon),/
(slash),|
(vertical bar), or any control characters (\u0000-\u001f
|\u007f-\u009f
). Also, it must not be the literal stringarn
.Type: String
Length Constraints: Minimum length of 1. Maximum length of 256.
Required: Yes
- workflowType
-
The type of the workflow to start.
Type: WorkflowType object
Required: Yes
Response Syntax
{
"runId": "string"
}
Response Elements
If the action is successful, the service sends back an HTTP 200 response.
The following data is returned in JSON format by the service.
- runId
-
The
runId
of a workflow execution. This ID is generated by the service and can be used to uniquely identify the workflow execution within a domain.Type: String
Length Constraints: Minimum length of 1. Maximum length of 64.
Errors
For information about the errors that are common to all actions, see Common Errors.
- DefaultUndefinedFault
-
The
StartWorkflowExecution
API action was called without the required parameters set.Some workflow execution parameters, such as the decision
taskList
, must be set to start the execution. However, these parameters might have been set as defaults when the workflow type was registered. In this case, you can omit these parameters from theStartWorkflowExecution
call and Amazon SWF uses the values defined in the workflow type.Note
If these parameters aren't set and no default parameters were defined in the workflow type, this error is displayed.
HTTP Status Code: 400
- LimitExceededFault
-
Returned by any operation if a system imposed limitation has been reached. To address this fault you should either clean up unused resources or increase the limit by contacting AWS.
HTTP Status Code: 400
- OperationNotPermittedFault
-
Returned when the caller doesn't have sufficient permissions to invoke the action.
HTTP Status Code: 400
- TypeDeprecatedFault
-
Returned when the specified activity or workflow type was already deprecated.
HTTP Status Code: 400
- UnknownResourceFault
-
Returned when the named resource cannot be found with in the scope of this operation (region or domain). This could happen if the named resource was never created or is no longer available for this operation.
HTTP Status Code: 400
- WorkflowExecutionAlreadyStartedFault
-
Returned by StartWorkflowExecution when an open execution with the same workflowId is already running in the specified domain.
HTTP Status Code: 400
Examples
StartWorkflowExecution Example
This example illustrates one usage of StartWorkflowExecution.
Sample Request
POST / HTTP/1.1
Host: swf.us-east-1.amazonaws.com
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.25) Gecko/20111212 Firefox/3.6.25 ( .NET CLR 3.5.30729; .NET4.0E)
Accept: application/json, text/javascript, */*
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Connection: keep-alive
Content-Type: application/x-amz-json-1.0
X-Requested-With: XMLHttpRequest
X-Amz-Date: Sat, 14 Jan 2012 22:45:13 GMT
X-Amz-Target: SimpleWorkflowService.StartWorkflowExecution
Content-Encoding: amz-1.0
X-Amzn-Authorization: AWS3 AWSAccessKeyId=AKIAIOSFODNN7EXAMPLE,Algorithm=HmacSHA256,SignedHeaders=Host;X-Amz-Date;X-Amz-Target;Content-Encoding,Signature=aYxuqLX+TO91kPVg+jh+aA8PWxQazQRN2+SZUGdOgU0=
Referer: http://swf.us-east-1.amazonaws.com/explorer/index.html
Content-Length: 417
Pragma: no-cache
Cache-Control: no-cache
{
"domain": "867530901",
"taskList": {
"name": "specialTaskList"
},
"taskPriority": "100",
"taskStartToCloseTimeout": "600",
"workflowId": "20110927-T-1",
"childPolicy": "TERMINATE",
"executionStartToCloseTimeout": "1800",
"input": "arbitrary-string-that-is-meaningful-to-the-workflow",
"workflowType": {
"version": "1.0",
"name": "customerOrderWorkflow"
},
"tagList": [
"music purchase",
"digital",
"ricoh-the-dog"
]
}
Sample Response
HTTP/1.1 200 OK
Content-Length: 48
Content-Type: application/json
x-amzn-RequestId: 6c25f6e6-3f01-11e1-9a27-0760db01a4a8
{
"runId": "1e536162-f1ea-48b0-85f3-aade88eef2f7"
}
See Also
For more information about using this API in one of the language-specific AWS SDKs, see the following: