Globus Automate Overview¶
The Globus Automate platform provides tools and services which can be used to create reliable processes for research data management. The platform builds on the foundation of Globus capabilities such as Authorization and Data Transfer.
The
Automate Platform introduces a few key concepts which may then be extended and
combined to create custom processes solving particular research data management
problems. These concepts are Action Providers, Actions, and Flows.
Read on to learn about how Flows orchestrate Action Providers together
in order to create Actions that perform the actual automation.
Use Cases¶
The key to the platform is enabling users to orchestrate multiple processing
steps into a single workflow, or Flow. Some of these steps are provided by
Globus Automate and othes of which may be custom implementations supporting
a specific need. Examples of these workflows might be:
Automatically detect data output from scientific instruments which is then transferred, processed, and indexed.
Provide a curated pipeline for description, annotation and publication of research datasets.
Run data transfers on a recurring schedule.
Action Providers¶
An Action Provider is an HTTP accessible service which acts as a single step
in a process and implements the Action Provider Interface. When
an Action Provider is invoked, it creates (or “provides”) an Action
which represents a single unit of work. Examples of units of work are running a
file transfer using Globus Transfer or ingesting data into Globus
Search.
Each Action Provider expects to be invoked with parameters
particular to the service it provides. To support usability and discovery, each
can be introspected to determine what its input schema or input properties
are. Introspection also provides information such as who operates the Action
Provider, descriptive text on the service it provides, and who can use the
service. Access to Action Providers and their invocation is controlled via
Globus Auth. Some of these services may be synchronous meaning that an
invocation will complete in the context of the HTTP request that triggered it.
Other services support asynchronous activities, meaning that the invocation
will persist beyond the HTTP request that invoked it and the the caller must
monitor the Action for updates on when it is completed and its result.
Globus operates a series of these Action Providers available for
public use. For a full list of these Action Providers, see
section Globus Action Providers. Globus also supports users writing
their own Action Providers via the Globus Action Provider Toolkit - a Python
SDK that makes it easy to provide custom services that can be tied
into the Globus Automate ecosystem of services.
These Action Providers form the foundation of Globus Automate and are
primarily used by referencing their URLs in Flows.
Globus Automate allows users to flexibly piece together these individual
services to create reliable high level workflows.
Actions¶
An Action represents a single, discrete invocation of an Action
Provider. It is record of an operation and includes details for its result,
its current execution status, and metadata dictating which Globus Auth
identities are allowed to read or modify the Action’s state. Globus
Automate services allow orchestrating these individual Actions into robust
processes that can tolerate their distinct execution states, including success
and failure. Users will not often need to operate on Actions directly,
rather, the User will create a Run of a Flow and the Run will invoke
Action Providers, creating Actions as necessary to accomplish the
automation.
Flows¶
A Flow represents a single process that orchestrates a series of services
into a self contained operation. One can think of a Flow as a
declaratively defined ordering of Action Providers with condition handling
to define expected success or failure scenarios.
A Flow may be defined and deployed to the Flows service by any user.
When deploying, the user may control which other users can discover the Flow
and separately, which users can run the Flow. All access control is provided
by Globus Auth. Thus, Flows can easily and safely be shared among users.
Once deployed, the Flow will receive a HTTP-accessible Flow URL which
makes it available for use in Globus Automate.
It may also be interesting to note that once deployed, the Flow will
implement the Action Provider Interface. What this means is that a Flow
is technically a form of Action Provider, and as such it can be referenced
by other Flows by its Flow URL. This allows for modularity in defining
Flows and in a separation of concerns where SubFlows can be trusted to
provide some process or behavior.
When users run an instance of the Flow, we call that a Run. A
Run shares the Action interface, supporting operations such as viewing
its status, cancelling its execution, and removing its execution state. This
allows for common tooling and terminology for working with Runs and
Actions. In general, any operation available on an Action will be
possible on a Run and vice versa.
Globus Automate imposes no restrictions on how long a Run may execute or
on the number of units of work defined in a Flow. We support long running
Runs by providing support for monitoring and status updates.