# Treasure Workflow Prerequisites and Limitations

Review these Treasure Workflow prerequisites and limitations to understand what you can and cannot accomplish with workflows.

* [Prerequisites](/requirements-and-limitations/treasure-workflow-prerequisites-and-limitations#TreasureWorkflowPrerequisitesandLimitations-Prerequisites)
* [Limitations](/requirements-and-limitations/treasure-workflow-prerequisites-and-limitations#TreasureWorkflowPrerequisitesandLimitations-Limitations)
* [Unsupported Digdag Features](/requirements-and-limitations/treasure-workflow-prerequisites-and-limitations#TreasureWorkflowPrerequisitesandLimitations-DigdagSyntaxLimitations)
* [Treasure Workflow Service Limits](/requirements-and-limitations/treasure-workflow-prerequisites-and-limitations#TreasureWorkflowPrerequisitesandLimitations-TreasureWorkflowServiceLimits)


# Prerequisites

Before you start creating a Treasure Workflow, you must have a database and table in Treasure Data.

# Limitations

## Unsupported Digdag Features

Treasure Workflow is based on Digdag, but following features are not supported:

* td> operator's download_file parameter for downloading query results locally. Instead, use the Treasure Data result export functionality
* sh> for running shell scripts
* rb> for running ruby scripts
* embulk> for running arbitrary Embulk jobs (but you can use td_load> for importing bulk data into Treasure Data)
* emr> for running Amazon EMR jobs
* param_get> for getting persistent data from ParamServer and set it as a value of store parameters
* param_set> for setting a value into a ParamServer as persistent data


`py>` is the only supported custom script.

## Treasure Workflow Service Limits

TD Workflow is designed to provide a scalable and flexible solution for managing your data pipelines in a cloud-hosted environment.

### Limits of Use

To ensure optimal and fair processing, the following limits exist:

* A maximum of 30 tasks are running concurrently per account. All other tasks get queued and are issued on a first-come-first-served basis.
* The maximum size of a project archive is 10 MB.
* 12,000 Saved Workflows. Over 12,000, and not all workflows will load within our Workflow UI. They are still accessible via CLI.
* The maximum total number of tasks in an attempt is 1,000.
* The maximum length of a task's full name is 640 bytes.
* Maximum attempts per account are:
  * US - 200
  * Tokyo - 200
  * EU - 300
  * All other regions - 100
* The period of time until a running task is killed is 1 day (24 hours).
* The period of time until a running attempt is killed is 7 days.
* The maximum response size for a td> task is 4 MB.
* The maximum response size for a http> task is 1 MB.
* The maximum response size for a http_call> task is 2 MB.
* The maximum output size for a py> task (Custom Scripts), including exported variables and any generated tasks, is 36 MB.
* The total response size for a td_for_each> task is 16 MB.


### Advised Limits of Use

For better performance of the TD Console Workflow, try to stay below the following limits:

* 200 Saved Workflows
* 400 Tasks in a Workflow


These limits are subject to change if there are changes to the configuration of Treasure Data capacity.

See also: [List of Upper Limits (MAX) on Treasure Data](/requirements-and-limitations/list-of-upper-limits-max-on-treasure-data)