StevenMMortimer / pfa-lambda

Dependencies for Deploying PFA Scoring Engine on AWS Lambda

pfa-lambda

A template for executing PFA on AWS Lambda to create a serverless, scalable analytical API.

Getting Started Quickly

If you want to test running PFA on AWS Lambda, clone this project, then zip it and upload to the AWS Console.

git clone [e-mail]:ReportMort/pfa-lambda.git
zip -r my-lambda-deploy.zip .

If you test this package in the AWS console, it should return 103.14 the result of our function which is hard-coded to accept 3.14 and then apply a PFA routine that adds 100 to return 103.14. You can use the AWS Hello World testing template which provides 3 dummy key-value pairs, but no key-values are required.

A More Realistic Example

In the script lambda_function.py a simple PFA routine is supplied directly as hand-writter, hard-coded text. Many machine learning models are complex algorithms that would not be hard-coded text. The model would be created and translated to PFA using a producer so that the logic would be saved in a separate file. Your model could be saved in an S3 bucket (with versioning) and called. For an example, check out model-from-s3.py. If you want to use this function, make sure to update the handler on AWS to be model-from-s3.py.lambda_handler and replace the bucket and key with the bucket and filename of your model on S3. This function depends on the event JSON input, therefore, the key-values for each model predictor variable must be provided and are directly paseed into the PFA engine to produce the score.

Troubleshooting

1. Check the selected Runtime for your lambda is Python 2.7
2. Check the name of the .py file in your root directory and ensure that it matches the handler specification in the AWS console (i.e. The filename.handler-method value in your function.)
3. If you see the message "errorMessage": "Unable to import module 'lambda_function'", make sure that the permissions of all files inside your .zip package are at least 444. The file and directory permissions every file in your deployment package (the .zip file) must be readable globally.

How This Deployment Package Was Made

This deployment package was created by following the instructions on AWS: http://docs.aws.amazon.com/lambda/latest/dg/lambda-python-how-to-create-deployment-package.html

More specifically, by running the following code:

mkdir my-pfa-lambda-module
cd my-pfa-lambda-module
pip install titus -t .

If you're using OS X and Homebrew you will need to specify a setup.cfg file. Here are the complete instructions for compiling:

mkdir my-pfa-lambda-module
cd my-pfa-lambda-module
touch setup.cfg
echo "[install]" >> setup.cfg
echo "prefix=" >> setup.cfg
pip install titus -t .