ME1QO0QNUDFU1QJB.mp4
Poll Me is an app open for all and developed as part of the CSC 510 Software Engineering Project 1. Want to get the opinion of many people on a certain matter, but haven't found a device that supports a large number of users yet? Then Poll Me is the right place for you. This app enables the creation of robust polls that support the use of a large number of users. Each host can create their own virtual room where they can publish their questions and share them with a large number of people. With pre-built survey templates, different survey types can be created and the results can be viewed by both host and player after answering the question.
The backend API is deployed on AWS Lambda using the serverless framework. Automated deploys are setup via a Github action that detects pushes to the main branch in the backend directory present in the project root. The action performs the following steps
- Install dependencies using
npm install - Generate prisma client(more about Prisma ORM in
./backend/README.md) - Push pending migrations to the database
- Deploy the service on AWS Lambda
The above action requires the following environment variables to be set
DATABASE_URL(URL of your postgres database)SERVERLESS_ACCESS_KEY(Access key for the serverless framework generated from the serverless dashboard)JWT_SECRET(Key used to sign auth tokens using JWT)ALLOWED_ORIGIN(Origins that are allowed via CORS)
When a service is deployed to AWS via the serverless framework, the following things happen
- Code is zipped and pushed to an S3 bucket
- API gateway service is created(as we use
httpevents for our lambda functions) - An aws lambda function is created/updated for each function defined in the
serverless.ymlfile
Frontend of the application is deployed on Netlify. Netlfiy detects changes to the front end and creates a production optimized build by running the command
npm run build
The static site assets are then served via Netlify's CDNs.
Note: There are many other providers that provide static site deployments like Vercel, AWS Amplify, etc that can be swapped for Netlify in this project
-
Switch to backend directory
cd backend -
Install dependencies
npm i -
Create and populate
.envfile from theenv.exampletemplate -
Generate prisma client
npx prisma generate -
Start local serverless API
serverless offline
Performing database changes(Refer prisma docs)
-
Make your schema changes in the
prisma/schema.prisma -
To create a migration, use the command
npx prisma migrate dev --name <migration_name>
-
Switch to frontend directory
cd frontend -
Install dependencies
npm install -
Create and populate
.envfile from theenv.exampletemplate -
Start local serverless API
npm run start
- Designing the Wireframe
- Basic architecture design and implementation
- Backend API implemented using serverless framework
- Front end mobile UI implemented using React
- Database design and schema implementation using Prisma
Live preview available at https://gracious-swirles-4a8c61.netlify.app
A list of future tasks are described in the issues section of this repository
All the architecture decisions in this project have been motivated with scalability in mind. Hence, we chose serverless for our backend and a Jamstack compatible framework(React) for our front end. Even though these are highly scalable and robust, there are certain parts of the application that could cause bottlenecks at scale
Database connections: , Each serverless function instance that runs requires it's own database connection. This can cause issues at scale as database connections are often quite limited. Following are certain remedies
- Each serverless function would push their intent into a queue when counting votes. A seperate consumer lambda could then aggregate these votes and count them together
- Another solution could be to use database connection pools to manage and preserve connections
Het Thakkar
Asha Khatri
Lorenz Scheller
Neelkanth Tripathi
Divyank Gupta