Simple Queue Service (SQS) Deep-Dive

March 9, 2021 / Eternal Team

SQS is a Polling service in AWS.
SQS is fast, reliable and fully managed message queue service.
It is a web service that gives you access to a message queue that store message waiting to be processed.
It offers a reliable, highly scalable hosted queue for storing message between server.
It allows the decoupling of application components such that a failure in one component does not cause a bigger problem to application functionality.
Using SQS, you can no longer need a highly available message cluster or the burden of running it.
You can delete all messages in SQS without deleting the SQS queue itself.
You can use an application on EC2 instance to read and process the SQS queue message.
The application on EC2 instance can process the SQS message than post the results to other SQS queue or other AWS Service.

AWS Queue Types

Standard Queue	FIFO queue
High or unlimited throughput At least one delivery Duplicity is not possible Best offer ordering	Limited throughput Exactly one processing Duplicity is possible First in first out ordering

As we know SQS is polling services from AWS.

There are two types of pulling.

Short polling – A request returns immediately even if a queue is empty and it does not wait for the message to appear in the queue.

Long polling – long-polling does not return a response until a message arrives in the message queue.

SQS Pricing

Billing is based on the API request. The first 1 million monthly requests are free. After that pricing is accordingly to the region which is mentioned at the official AWS page. For example, In Mumbai region