Short Polling vs Long Polling in AWS SQS: Key Differences and Usage

In AWS SQS, short polling immediately returns messages available in the queue, possibly empty if none are ready, while long polling waits up to a specified timeout for messages to arrive before returning. Long polling reduces empty responses and lowers costs by minimizing unnecessary requests.

Quick Comparison

This table summarizes the main differences between short polling and long polling in AWS SQS.

Factor	Short Polling	Long Polling
Wait Time	Returns immediately	Waits up to 20 seconds for messages
Empty Responses	More frequent	Less frequent
Cost Impact	Higher due to more requests	Lower due to fewer requests
Latency	Lower for available messages	Potentially higher due to wait
Use Case	Quick checks or low traffic	Efficient for steady or bursty traffic

Key Differences

Short polling sends a request to the SQS queue and immediately returns any available messages. If no messages are available, it returns an empty response right away. This can lead to many empty responses and higher costs because your application keeps polling frequently.

Long polling improves efficiency by allowing the request to wait up to a specified timeout (up to 20 seconds) for messages to arrive before returning. This reduces the number of empty responses and lowers the number of API calls, saving cost and reducing unnecessary load.

While short polling is faster when messages are already available, long polling is generally preferred for most applications because it balances latency and cost by waiting briefly for messages instead of returning empty results immediately.

Code Comparison

Example of short polling using AWS SDK for Python (boto3) to receive messages from an SQS queue.

python

import boto3

sqs = boto3.client('sqs')
queue_url = 'https://sqs.us-east-1.amazonaws.com/123456789012/MyQueue'

response = sqs.receive_message(
    QueueUrl=queue_url,
    MaxNumberOfMessages=1,
    WaitTimeSeconds=0  # Short polling
)

messages = response.get('Messages', [])
if messages:
    print('Received message:', messages[0]['Body'])
else:
    print('No messages received')

Output

No messages received

Long Polling Equivalent

Example of long polling using AWS SDK for Python (boto3) to receive messages from an SQS queue with a 10-second wait time.

python

import boto3

sqs = boto3.client('sqs')
queue_url = 'https://sqs.us-east-1.amazonaws.com/123456789012/MyQueue'

response = sqs.receive_message(
    QueueUrl=queue_url,
    MaxNumberOfMessages=1,
    WaitTimeSeconds=10  # Long polling
)

messages = response.get('Messages', [])
if messages:
    print('Received message:', messages[0]['Body'])
else:
    print('No messages received after waiting')

Output

No messages received after waiting

When to Use Which

Choose short polling when your application needs immediate responses and can tolerate empty results, such as in low-traffic or testing scenarios.

Choose long polling for production workloads where reducing empty responses and API calls saves cost and improves efficiency, especially when message arrival is unpredictable or bursty.

Long polling is generally the best practice for most AWS SQS consumers to balance latency and cost.

Key Takeaways

Long polling waits for messages up to 20 seconds, reducing empty responses and costs.

Short polling returns immediately and may cause more empty responses and higher costs.

Use long polling for efficient, cost-effective message processing in most cases.

Short polling suits quick checks or low-traffic scenarios needing immediate response.

AWS SDKs support both by setting the WaitTimeSeconds parameter in receive_message.