AWS Flow Framework for Ruby Samples and Recipes

This project contains sample code and recipes for the AWS Flow Framework for Ruby.

• Prerequisites
• Downloading the Sample Code
• Samples
• Recipes
• For More Information

License

All code in this repository, unless otherwise specified, is offered under the Apache 2.0 license. For more information, see the LICENSE.txt file accompanying this repository or view the license terms online at http://www.apache.org/licenses/LICENSE-2.0.

Downloading the Sample Code

To view or download the code for all of the AWS Flow Framework for Ruby recipes and samples, go to:

• https://github.com/awslabs/aws-flow-ruby-samples

Prerequisites for Running the Samples

The AWS Flow Framework for Ruby is required, which can be obtained and installed using the information here:

• https://aws.amazon.com/swf/flow/

If you already have Ruby and RubyGems installed, you can install the framework and all of the gems required by the samples by opening a terminal window, changing to the directory where you've cloned or downloaded the samples, and typing:

bundle install

This will install all of the requirements that are listed in the Gemfile in the repository's base directory.

For more information about setting up the AWS Flow Framework for Ruby, see Installing the AWS Flow Framework for Ruby in the AWS Flow Framework for Ruby Developer Guide.

Samples

booking

The Booking sample demonstrates a synchronization workflow pattern. It waits for two activities to complete: a car reservation and airline reservation. When both activities complete, it sends a confirmation. All activities are performed asynchronously.

Code + info: samples/booking

cron

The Cron sample runs an activity periodically based on a cron expression.

Code + info: samples/cron

cron_with_retry

The CronWithRetry sample demonstrates how to run a scheduled task with exponential_retry options. Once the workflow is complete, continue_as_new is used to re-run the workflow at the next scheduled time.

Code + info: samples/cron_with_retry

deployment

The Deployment sample illustrates the deployment of a set of application components through a workflow. A YAML configuration file is used to describe the application stack. The workflow takes this description as input and simulates the deployment of the components specified in it.

Code + info: samples/deployment

file_processing

The FileProcessing sample demonstrates a media processing use case. The workflow downloads a file from an Amazon S3 bucket, creates a .zip file and then uploads the file back to Amazon S3. The task routing feature in Amazon SWF is illustrated in this sample.

Code + info: samples/file_processing

hello_world

The HelloWorld sample uses a very simple workflow that calls an activity to print Hello World. It shows basic usage of the framework, including implementing activities and workflow coordination logic and building workers to run the workflow and activities.

Code + info: samples/hello_world

periodic

The Periodic sample periodically executes an activity in a long-running workflow. The ability to continue executions as new executions so that an execution can run for very extended periods of time is demonstrated.

Code + info: samples/periodic

split_merge

The SplitMerge sample demonstrates a parallel split followed by a simple merge workflow pattern. It spawns a number of worker activities which are then merged using wait_for_all.

Code + info: samples/split_merge

Recipes

branch

The Branch code provides a recipe to execute a dynamically-determined number of activities concurrently.

Code + info: recipes/branch

child_workflow

The ChildWorkflow code provides a recipe to start a child workflow inside a workflow execution.

Code + info: recipes/child_workflow

choice

The Choice recipes show how to use a choice to execute one of several activities, or to execute multiple activities from a larger group.

Code + info: recipes/choice

conditional_loop

The ConditionalLoop code provides a recipe to execute a dynamically-determined number of activities concurrently.

Code + info: recipes/conditional_loop

handle_error

The HandleError code provides recipes to respond to exceptions in asynchronous activities depending on exception type and to handle exceptions in asynchronous activities and perform cleanup.

Code + info: recipes/handle_error

human_task

The HumanTask code provides a recipe to Complete an Activity Task Manually.

Code + info: recipes/human_task

pick_first_branch

The PickFirstBranch code provides a recipe to execute multiple activities concurrently and pick the fastest.

Code + info: recipes/pick_first_branch

retry_activity

The RetryActivity recipes show how to:

• apply a retry policy to all invocations of an activity
• specify a retry policy for an activity client, a block of code, or for a specific invocation of an activity
• retry activities without jitter, or with custom jitter logic
• retry activities with custom retry policies

Code + info: recipes/retry_activity

wait_for_signal

The WaitForSignal code provides a recipe to wait for an external signal and take a different code path if the signal is received.

Code + info: recipes/wait_for_signal

For More Information

For more information about the Amazon Simple Workflow service and the Amazon Flow Framework for Ruby, consult the following resources:

• AWS Flow Framework for Ruby Developer Guide
• AWS Flow Framework for Ruby API Reference
• AWS Flow Framework
• Amazon Simple Workflow Service