Amazon Simple Workflow Service Limits

Maximum registered domains – 100

This limit includes both registered and deprecated domains.

Maximum workflow and activity types – 10,000 each per domain

This limit includes both registered and deprecated types.

API call limit – Beyond infrequent spikes, applications may be throttled if they make a large number of API calls in a very short period of time.

Maximum request size – 1 MB per request

This is the total data size per Amazon SWF API request, including the request header and all other associated request data.

Maximum open workflow executions – 100,000 per domain

This count includes child workflow executions.

Maximum workflow execution time – 1 year

Maximum workflow execution history size – 25,000 events

Maximum child workflow executions – 1,000 per workflow execution.

Workflow execution idle time limit – 1 year (constrained by workflow execution time limit)

You can configure workflow timeouts to cause a timeout event to occur if a particular stage of your workflow takes too long.

Workflow retention time limit – 90 days

After this time, the workflow history can no longer be retrieved or viewed. There is no further limit to the number of closed workflow executions that are retained by Amazon SWF.

Maximum pollers per task list – 100 per host, per tasklist

There are 10 hosts available, so the limit of pollers per task list is 1000 total. However, if a single host receives 101 pollers on a particular task list, a LimitExceededException will result.

Maximum task execution time – 1 year (constrained by workflow execution time limit)

You can configure activity timeouts to cause a timeout event to occur if a particular stage of your activity task execution takes too long.

Maximum time SWF will keep a task in the queue – 1 year (constrained by workflow execution time limit)

You can configure default activity timeouts during activity registration that will cause a timeout event to occur if a particular stage of your activity task execution takes too long. You can also override the default activity timeouts when you schedule an activity task in your decider code.

Maximum open activity tasks – 1,000 per workflow execution.

This limit includes both activity tasks that have been scheduled and those being processed by workers.

Maximum open timers – 1,000 per workflow execution

Maximum input/result data size – 32,000 characters

This limit affects activity or workflow execution result data, input data when scheduling activity tasks or workflow executions, and input sent with a workflow execution signal.

Maximum decisions in a decision task response – varies

Due to the 1 MB limit on the maximum API request size, the number of decisions returned in a single call to RespondDecisionTaskCompleted will be limited according to the size of the data used by each decision, including the size of any input data provided to scheduled activity tasks or to workflow executions.

Throttling limits for us-east-1

Throttling limits for other regions