16-long-short-polling

README

Implementing Short Polling and Long Polling

1. Mock EC2 creation with sleep

Create a table p_servers to store the status of the EC2.

CREATE TABLE IF NOT EXISTS p_servers (server_id INT PRIMARY KEY AUTO_INCREMENT, status VARCHAR(20));

createEC2 function mimics the stages of an EC2 server creation, updating a database table (p_servers) with status values (TODO, IN PROGRESS, and DONE) over time.

POST /servers:

• Returns a JSON response ({"submitted": "ok"})
• Implies that the server creation would be initiated here.

2. Define API that client can do to short poll the status

/short/status/:server_id is the endpoint where the client keeps polling frequently to get the server’s latest status.

GET /short/status/:server_id (Short Polling):

• Takes a server_id and retrieves the latest status from the p_servers table.
• Client repeatedly makes this request to get updates on the server's status.

3. Define API that client can do to long poll the status

/long/status/:server_id holds the request open and only responds once there’s a change in status.

GET /long/status/:server_id (Long Polling):

• The server will continue checking the status in a loop until it detects a status change.
• The client makes a single request and waits for a response only when the status has actually changed. This reduces the need for constant polling.

Result

Short poll and Long poll status