DistributedMap

class aws_cdk.aws_stepfunctions.DistributedMap(scope, id, *, item_batcher=None, item_reader=None, label=None, map_execution_type=None, result_writer=None, tolerated_failure_count=None, tolerated_failure_count_path=None, tolerated_failure_percentage=None, tolerated_failure_percentage_path=None, comment=None, input_path=None, item_selector=None, items_path=None, max_concurrency=None, max_concurrency_path=None, output_path=None, result_path=None, result_selector=None, state_name=None)

Bases: MapBase

Define a Distributed Mode Map state in the state machine.

A Map state can be used to run a set of steps for each element of an input array. A Map state will execute the same steps for multiple entries of an array in the state input.

While the Parallel state executes multiple branches of steps using the same input, a Map state will execute the same steps for multiple entries of an array in the state input.

A Map state in Distributed mode will execute a child workflow for each iteration of the Map state. This serves to increase concurrency and allows for larger workloads to be run in a single state machine.

See:

https://docs.aws.amazon.com/step-functions/latest/dg/concepts-asl-use-map-state-distributed.html

ExampleMetadata:

infused

Example:

distributed_map = sfn.DistributedMap(self, "Distributed Map State",
    max_concurrency=1,
    items_path=sfn.JsonPath.string_at("$.inputForMap")
)
distributed_map.item_processor(sfn.Pass(self, "Pass State"))
Parameters:

  • scope (Construct) –

  • id (str) – Descriptive identifier for this chainable.

  • item_batcher (Optional[ItemBatcher]) – Specifies to process a group of items in a single child workflow execution. Default: - No itemBatcher

  • item_reader (Optional[IItemReader]) – ItemReader. Configuration for where to read items dataset in S3 to iterate Default: - No itemReader

  • label (Optional[str]) – Label. Unique name for the Distributed Map state added to each Map Run Default: - No label

  • map_execution_type (Optional[StateMachineType]) – MapExecutionType. The execution type of the distributed map state This property overwrites ProcessorConfig.executionType Default: StateMachineType.STANDARD

  • result_writer (Optional[ResultWriter]) – Configuration for S3 location in which to save Map Run results. Default: - No resultWriter

  • tolerated_failure_count (Union[int, float, None]) – ToleratedFailureCount. Number of failed items to tolerate in a Map Run, as static number Default: - No toleratedFailureCount

  • tolerated_failure_count_path (Optional[str]) – ToleratedFailureCountPath. Number of failed items to tolerate in a Map Run, as JsonPath Default: - No toleratedFailureCountPath

  • tolerated_failure_percentage (Union[int, float, None]) – ToleratedFailurePercentage. Percentage of failed items to tolerate in a Map Run, as static number Default: - No toleratedFailurePercentage

  • tolerated_failure_percentage_path (Optional[str]) – ToleratedFailurePercentagePath. Percentage of failed items to tolerate in a Map Run, as JsonPath Default: - No toleratedFailurePercentagePath

  • comment (Optional[str]) – An optional description for this state. Default: No comment

  • input_path (Optional[str]) – JSONPath expression to select part of the state to be the input to this state. May also be the special value JsonPath.DISCARD, which will cause the effective input to be the empty object {}. Default: $

  • item_selector (Optional[Mapping[str, Any]]) – The JSON that you want to override your default iteration input (mutually exclusive with parameters). Default: $

  • items_path (Optional[str]) – JSONPath expression to select the array to iterate over. Default: $

  • max_concurrency (Union[int, float, None]) – MaxConcurrency. An upper bound on the number of iterations you want running at once. Default: - full concurrency

  • max_concurrency_path (Optional[str]) – MaxConcurrencyPath. A JsonPath that specifies the maximum concurrency dynamically from the state input. Default: - full concurrency

  • output_path (Optional[str]) – JSONPath expression to select part of the state to be the output to this state. May also be the special value JsonPath.DISCARD, which will cause the effective output to be the empty object {}. Default: $

  • result_path (Optional[str]) – JSONPath expression to indicate where to inject the state’s output. May also be the special value JsonPath.DISCARD, which will cause the state’s input to become its output. Default: $

  • result_selector (Optional[Mapping[str, Any]]) – The JSON that will replace the state’s raw result and become the effective result before ResultPath is applied. You can use ResultSelector to create a payload with values that are static or selected from the state’s raw result. Default: - None

  • state_name (Optional[str]) – Optional name for this state. Default: - The construct ID will be used as state name

Methods

add_catch(handler, *, errors=None, result_path=None)

Add a recovery handler for this state.

When a particular error occurs, execution will continue at the error handler instead of failing the state machine execution.

Parameters:

  • handler (IChainable) –

  • errors (Optional[Sequence[str]]) – Errors to recover from by going to the given state. A list of error strings to retry, which can be either predefined errors (for example Errors.NoChoiceMatched) or a self-defined error. Default: All errors

  • result_path (Optional[str]) – JSONPath expression to indicate where to inject the error data. May also be the special value JsonPath.DISCARD, which will cause the error data to be discarded. Default: $

Return type:

DistributedMap

add_prefix(x)

Add a prefix to the stateId of this state.

Parameters:

x (str) –

Return type:

None

add_retry(*, backoff_rate=None, errors=None, interval=None, jitter_strategy=None, max_attempts=None, max_delay=None)

Add retry configuration for this state.

This controls if and how the execution will be retried if a particular error occurs.

Parameters:

  • backoff_rate (Union[int, float, None]) – Multiplication for how much longer the wait interval gets on every retry. Default: 2

  • errors (Optional[Sequence[str]]) – Errors to retry. A list of error strings to retry, which can be either predefined errors (for example Errors.NoChoiceMatched) or a self-defined error. Default: All errors

  • interval (Optional[Duration]) – How many seconds to wait initially before retrying. Default: Duration.seconds(1)

  • jitter_strategy (Optional[JitterType]) – Introduces a randomization over the retry interval. Default: - No jitter strategy

  • max_attempts (Union[int, float, None]) – How many times to retry this particular error. May be 0 to disable retry for specific errors (in case you have a catch-all retry policy). Default: 3

  • max_delay (Optional[Duration]) – Maximum limit on retry interval growth during exponential backoff. Default: - No max delay

Return type:

DistributedMap

bind_to_graph(graph)

Register this state as part of the given graph.

Don’t call this. It will be called automatically when you work with states normally.

Parameters:

graph (StateGraph) –

Return type:

None

item_processor(processor, *, execution_type=None, mode=None)

Define item processor in a Distributed Map.

A Distributed Map must have a non-empty item processor

Parameters:

  • processor (IChainable) –

  • execution_type (Optional[ProcessorType]) – Specifies the execution type for the Map workflow. If you use the Map class, you must provide this field if you specified DISTRIBUTED for the mode sub-field. If you use the DistributedMap class, this property is ignored. Use the mapExecutionType in the DistributedMap class instead. Default: - no execution type

  • mode (Optional[ProcessorMode]) – Specifies the execution mode for the Map workflow. Default: - ProcessorMode.INLINE if using the Map class, ProcessorMode.DISTRIBUTED if using the DistributedMap class

Return type:

DistributedMap

next(next)

Continue normal execution with the given state.

Parameters:

next (IChainable) –

Return type:

Chain

to_state_json()

Return the Amazon States Language object for this state.

Return type:

Mapping[Any, Any]

to_string()

Returns a string representation of this construct.

Return type:

str

Attributes

end_states

Continuable states of this Chainable.

id

Descriptive identifier for this chainable.

node

The tree node.

start_state

First state of this Chainable.

state_id

Tokenized string that evaluates to the state’s ID.

Static Methods

classmethod filter_nextables(states)

Return only the states that allow chaining from an array of states.

Parameters:

states (Sequence[State]) –

Return type:

List[INextable]

classmethod find_reachable_end_states(start, *, include_error_handlers=None)

Find the set of end states states reachable through transitions from the given start state.

Parameters:

  • start (State) –

  • include_error_handlers (Optional[bool]) – Whether or not to follow error-handling transitions. Default: false

Return type:

List[State]

classmethod find_reachable_states(start, *, include_error_handlers=None)

Find the set of states reachable through transitions from the given start state.

This does not retrieve states from within sub-graphs, such as states within a Parallel state’s branch.

Parameters:

  • start (State) –

  • include_error_handlers (Optional[bool]) – Whether or not to follow error-handling transitions. Default: false

Return type:

List[State]

classmethod is_construct(x)

Checks if x is a construct.

Use this method instead of instanceof to properly detect Construct instances, even when the construct library is symlinked.

Explanation: in JavaScript, multiple copies of the constructs library on disk are seen as independent, completely different libraries. As a consequence, the class Construct in each copy of the constructs library is seen as a different class, and an instance of one class will not test as instanceof the other class. npm install will not create installations like this, but users may manually symlink construct libraries together or use a monorepo tool: in those cases, multiple copies of the constructs library can be accidentally installed, and instanceof will behave unpredictably. It is safest to avoid using instanceof, and using this type-testing method instead.

Parameters:

x (Any) – Any object.

Return type:

bool

Returns:

true if x is an object created from a class which extends Construct.

classmethod is_distributed_map(x)

Return whether the given object is a DistributedMap.

Parameters:

x (Any) –

Return type:

bool

classmethod prefix_states(root, prefix)

Add a prefix to the stateId of all States found in a construct tree.

Parameters:
Return type:

None