Code360 powered by Coding Ninjas X Code360 powered by Coding Ninjas X
Table of contents
Benefits of Using Amazon SQS 
Difference between Amazon SQS, MQ, and SNS
Basic Amazon SQS Architecture
Distributed Queue 
Message Lifecycle 
Message Delivery 
Message Deletion 
Why uses SQS over the API calls?
Frequently Asked Questions
Is message ordering available in Amazon SQS?
Is Amazon SQS able to ensure message delivery?
What is the difference between Amazon SQS and Amazon Kinesis Streams? 
Is Amazon making use of Amazon SQS for its own apps?
Last Updated: Mar 27, 2024


Master Python: Predicting weather forecasts
Ashwin Goyal
Product Manager @


Amazon SQS is a distributed message queuing service launched as a test by in late 2004 and generally became available in mid-2006. It allows you to interact over the Internet by sending messages programmatically using web service apps. SQS is used to provide a highly scalable hosted message queue that addresses challenges emerging from the common producer-consumer problem or between producer and consumer connectivity.

Amazon SQS hosted queue that allows you to link and decouple distributed software systems and components. It is safe, durable, and available. Dead-letter queues and cost allocation tags are two typical Amazon SQS structures. It offers a general web services API that you may use with any programming language supported by the AWS SDK.

Benefits of Using Amazon SQS 

  • Security - You have complete control over who may send and receive messages from an Amazon SQS queue.
  • Server-side encryption (SSE) protects the contents of messages in queues using keys controlled by the AWS Key Management Service, allowing you to send sensitive data (AWS KMS).
  • Durability - Amazon SQS saves your messages on numerous servers to ensure security. Messages are delivered at least once in standard queues, whereas messages are processed precisely once in FIFO queues.
  • Availability — To allow highly concurrent access to messages and high availability for creating and consuming messages, Amazon SQS leverages redundant infrastructure.
  • Scalability — Amazon SQS can process each delayed request separately, scaling transparently to manage any demand surges or spikes without any provisioning instructions.
  • Reliability — During processing, Amazon SQS locks your messages so that numerous producers and consumers can send and receive messages simultaneously.
  • Customization - Your queues don't have to look the same; you may modify a queue's default delay. You can use Amazon Simple Storage Service (Amazon S3) or Amazon DynamoDB to store the contents of messages greater than 256 KB, with Amazon SQS keeping a reference to the Amazon S3 object, or you can divide a large message into smaller ones.

Also see, Amazon Hirepro

Get the tech career you deserve, faster!
Connect with our expert counsellors to understand how to hack your way to success
User rating 4.7/5
1:1 doubt support
95% placement record
Akash Pal
Senior Software Engineer
326% Hike After Job Bootcamp
Himanshu Gusain
Programmer Analyst
32 LPA After Job Bootcamp
After Job

Difference between Amazon SQS, MQ, and SNS

Amazon SQS and Amazon SNS are highly scalable queue and subject services that don't require you to set up message brokers and are easy to use. These services are recommended for new applications that require practically limitless scalability and accessible APIs.

Amazon MQ is a managed message broker solution that works with various other message brokers. We propose Amazon MQ to convert applications from current message brokers that depend on APIs like JMS or protocols like AMQP, MQTT, OpenWire, and STOMP.

Basic Amazon SQS Architecture

The components of a distributed messaging system are described in this section, and the lifespan of an Amazon SQS message.

Distributed Queue 

The components of your distributed messaging system, your queue (spread across Amazon SQS servers), and the messages in the queue are the three primary components of a distributed messaging system.

Your system contains numerous producers (components that deliver messages to the queue) and consumers in the example below (components that receive messages from the queue). The queue (which houses messages A through E) saves the messages on various Amazon SQS servers in a redundant manner.


Message Lifecycle 

The following scenario describes the lifespan of an Amazon SQS message in a queue from creation through deletion.


  • Message A is sent to a queue by a producer (component 1), and the message is redundantly disseminated across Amazon SQS servers.
  • When a consumer (component 2) is ready to handle messages, it consumes them from the queue and returns message A. Message A remains in the queue and is not returned to future receive requests for the length of the visibility timeout while it is processed.
  • When the visibility timeout expires, the consumer (component 2) deletes message A from the queue to prevent the message from being received and processed again.


Amazon SQS provides authentication protocols to enable safe data processing. This is done using Amazon's Amazon Web Services (AWS) identity, which requires customers to have an AWS account with To conduct identification, AWS gives a pair of associated identifiers, your AWS access keys, to an AWS-enabled account. A public 20-character Access Key is the initial identification. This key is used to identify the user in an AWS service request. If the user isn't utilizing SOAP (protocol) with WS-Security, the Secret Access Key is used to generate a digital signature. A 40-character secret identification is the Secret Access Key. AWS looks up an account's Secret Access Key using the Access Key ID given in a service request. then uses the key to create a digital signature. If they match, the user is regarded legitimate; if they don't, the authentication fails, and the request is ignored.

Message Delivery 

Amazon SQS assures delivery at least once. For redundancy and availability, messages are saved on numerous servers. If a message is sent when a server is unavailable, it may not be deleted from the queue of that server and may be reissued. As of 2007, Amazon SQS does not ensure that messages will be delivered in the sequence the sender sent them. If message ordering is crucial, the application must provide sequencing information in the messages so that they may be reordered after delivery.

Messages can be of any sort, and the information they carry isn't limited. Message bodies were initially restricted to 8KB, but on 2010-07-01, they were increased to 64KB, and then to 256KB on 2013-06-18. The user has a couple of alternatives to get around this constraint for bigger texts. A big message can be broken into many pieces and delivered individually, or the message data can be saved with merely a pointer to the data transmitted in the SQS message using Amazon Simple Storage Service (Amazon S3) or Amazon DynamoDB. For this reason, Amazon has made an Extended Client Library accessible. 

The service supports both infinite queues and message traffic.

Message Deletion 

SQS does not remove messages once they have been sent. A receipt handle is produced for each delivery and communicated to the receiver when a message is delivered. These receipts are delivered in addition to the communication, not with it. To remove a communication, SQS asks the recipient to produce the receipt. Only the message ID was required for message deletion before 2008. Hence this functionality is new. A message may be transmitted many times due to the dispersed nature of the system. To erase the news, you'll need the most recent receipt handle. Furthermore, the receipt handle may be subject to other validity limitations, such as being valid during the visibility timeout.

When a message is sent, it has a visibility timeout that prevents it from being consumed by other components. When a message is sent, the "clock" for the visibility timeout starts ticking, with the default period being 30 seconds. If the queue is not ordered to remove the message during this period, the message resurfaces and remains visible.

Each queue also has a retention option set to 4 days by default. Any message that has been in the queue for an extended period of time will be automatically removed. The user may change the retention time from 1 minute to 14 days. Any message that has been in the queue for longer than the new retention will be discarded if the retention is altered while messages are already in the queue.

Dropbox, Netflix, and Nextdoor are just a few examples of organizations that make substantial use of SQS. also makes extensive use of SQS.

Why uses SQS over the API calls?

  • Backpressure control - Consumers can choose the rate of processing. 
  • Fire and Forget - Publishers have no insight into client processing 
  • Eventual Guaranteed processing - Great for async and non-realtime apps. 
  • Application decoupling - decoupling service dependencies 


Frequently Asked Questions

Is message ordering available in Amazon SQS?

Yes. FIFO (first-in-first-out) queues ensure that messages are transmitted and received in the same sequence. You don't need to provide sequencing information in your messages if you utilize a FIFO queue. 

Is Amazon SQS able to ensure message delivery?

At least once delivery is provided by standard queues, which means that each message is sent at least once.

FIFO queues offer exactly-once processing, which implies that each message is sent just once and is available until it is processed and deleted by a consumer. There are no duplicates added to the queue.

What is the difference between Amazon SQS and Amazon Kinesis Streams? 

For storing messages as they flow between applications or microservices, Amazon SQS provides a dependable, highly scalable hosted queue. It helps you separate dispersed application components by moving data across them. Common middleware components such as dead-letter queues and poison-pill management are available with Amazon SQS. It also includes a general web services API that may be used with any programming language supported by the AWS SDK. Standard and FIFO queues are supported by Amazon SQS.

Amazon Kinesis Streams provide real-time large data processing as well as the ability to read and playback records across many Amazon Kinesis Applications.

Is Amazon making use of Amazon SQS for its own apps?

Yes. Amazon SQS is used by developers for a range of applications that process massive amounts of messages on a daily basis. Amazon SQS is used in key business operations at both and Amazon Web Services.


In this article, we briefly discussed the Introduction to SQS in AWS, and benefits of using Amazon SQS, and basic Amazon SQS architecture. 

Refer to our guided paths on Coding Ninjas Studio to learn more about DSA, Competitive Programming, JavaScript, System Design, etc. Enroll in our courses and refer to the mock test and problems available, interview puzzles, take a look at the interview experiences, and interview bundle for placement preparations.

Thank you for reading. 

Until then, Keep Learning and Keep improving.

Coding Ninjas is the one-stop solution for all the coding-related content. You can refer to these links. 

Previous article
Amazon Simple Workflow Service
Next article
AWS Agentless Discovery Connector
Live masterclass