Amazon SNS VS SQS

When it comes to developing software, Amazon Web Services (AWS) corresponds to a developer’s dream toolkit. It assists in the development of dependable, high-performing apps that can manage heavy workloads. Amazon Simple Notification Service (SNS) and Amazon Simple Queue Service (SQS) are two of the many services that AWS provides. These tools, which operate similarly to communication wizards, assist communication between various app components. Consider SNS as an instant messenger that can send messages to multiple recipients at once. However, SQS acts as a careful messenger, ensuring that messages are delivered in a well-organized manner even during congested times.

What is AWS SNS(Simple Notification Service)?

AWS Simple Notification Service (SNS) is a fully managed notification service provided by Amazon Web Services(AWS). The motive behind developing SNS is to help developers build scalable, reliable, and cost-effective applications by providing them with a simple and easy-to-configure notification system without worrying about the underlying infrastructure. AWS SNS works on the publisher-subscriber(pub-sub) model. With AWS SNS you can send notifications to various channels like mobile Devices (Android, iOS), Email, SMS, HTTP/HTTPS endpoints, AWS Simple Queue Service(SQS), etc.

What is AWS SQS(Simple Queue Service)?

AWS Simple Queue Service (AWS SQS) is a messaging queue service provided by Amazon Web Services(AWS). SQS supports the decoupling and asynchronous communication between various systems within a distributed architecture. The motive behind the SQS is to make a reliable and scalable method for transmitting messages between dissimilar software components. In Simpler Terms, AWS SQS works like temporary waiting lines for the messages, where messages are added to the queue by the sending component and users retrieve these messages for their further processing. So SQS temporarily stores the messages and separates the message generation and message consumption phase. Thus promoting asynchronous and decoupled communication between different parts of an application.

Difference Between AWS SNS And AWS SQS

The following are the differences between AWS SNS and AWS SQS:

Topic	AWS SNS	AWS SQS
Communication Type	Publisher/Subscriber Here messages/notifications are published to topics by notification producers and subscribers which have subscribed to this topic can instantly receive the messages	Point-to-Point Here messages/ notifications are produced by producers and stored in the temporary queue and consumers can independently retrieve those messages/notifications.
Message Delivery	SNS follows push mechanism where subscribers receives messages/notifications instantly.	SQS follows pull mechanism where messages/notifications are being pulled from the queue.
Message Retrieval	Subscribers/endpoints will recieve the messages/notifications instantly without any active retrieval	Consumers have to poll the queue independently to retrieve the messages/notifications
Message Retension	Messages/Notifications delivered in real time so do not persist messages/notifications	Messages/Notifications not deliverd in real time to consumers so it provide persistance,it will store the messages until completely processed or explicitly deleted
Use Case	Ideal for scenarios where instant messages/notifications delivery required to single or multiple receipients.ex:- mobile push notifications,broadcasting messages.	Ideal for scenarios where different parts of a system need to work independently.ex:-load balancing,task offloading etc.
Fan Out	SNS allows single message/notification to be delivered to multiple subscribers instantly without the need for the individual configurations for each receipient.	SQS doesn’t directly support fan-out,to achieve fan-out in SQS need to configure seperate queue for each consumer and required additional configuration for message/notification duplication.
Retry Mechanism	Incase of failed delivery to subscribers it automatically retries.	Here Consumers are responsible for handling retries.
Scaling Mechanism	It scales with the number of subscribers.	It scales with the volume of the messages.

What are the differences Between Amazon SQS, Amazon MQ and Amazon SNS?

The following are the some of the major aspects of differences among Amazon SQS, Amqzon MQ and Amazon SNS:

Features	Amazon SQS	Amazon MQ	Amazon SNS
Messaging Pattern	It works on Queue-based i.e., point-to-point	It also works on Queue based i.e., ( Point-to-Point )	It works on Topic based with publish and Subcribe model.
Protocol Support	It works with protocols such as HTTP/HTTPS , AWS SDKs	It works on protocols AMQP, MQTT, OpenWire, STOMP	It works on protocols such as HTTP/HTTPS, AWS SDKs
Message Retention	It is Configurable	It is Configurable	In this their is no retention, it only delivers the messages.
Messae Ordering	It provides best-effort ordering	It provides guaranteed ordering	It doesn’t guarantee about the ordering
Consumer Control	It is pooling by Consumers	It is dedicated to consumers instances	It will push to subscribed endpoints
Use Cases	It used in Decoupled Systems, Load Leveling	It used in Traditional messaging systems.	It used in broadcast messaging, eent-driven architecture.

What are the difference between SNS and Kafka?

The following are the differences between SNS and Kafka:

Features	Amazon SNS	Kafka
Type	It is fully managed messaging service	It is distributed streaming platform
Messaging Model	It follows Publish/Subscribe Model	It follows Publish/Subscribe model and Message Queue
Scalability	It has limited scaling options	It provides highly scalable features
Persistence	No message persistance	Messages are stored for configurable time
Ordering	It doesn’t follow no strict message ordering	It follows strict message ordering
Use Case	It used for instant notifications, Lightweight messaging	It used in Real-time data processing, event sourcing

When to Use Amazon SNS?

Amazon SNS (Simple Notification Service ) is a powerful messaging service that is designed for real-time managing high-throughput communication. The following are the some of the cases of when to use it.

• Instant Notifications: Amazon SNS will be a perfect choice when their is need to deliver the notifications instantly to a large scale of subscribers across multiple channels such as mobile devices, email, SMS and HTTP endpoints.
• Event-Driven Architectures: It is suitable for event-driven architecture based systems where event get triggered the notifications or updates has to sent with seamless communication.
• Scalable And Reliable Messaging: With the ability of Amazon SNS, it can handle the high messages throughput and seamless integration with other AWS services. Amazon SNS provides reliable and scalable messaging without the need for managing infrastructure.

When to Use Amazon SQS?

Amazon SQS (Simple Queue Service ) is ideal for managing the message queues in scenarios where you need reliable and scalable message processing. The following are the some of the cases where we use Amazon SQS:

• Scalability: Amazon SNS can be used for managing effortless scaling and for handling various workloads. It also ensures the responsiveness under heavy traffic without any manual interventions.
• Reliability: It can be used in built-in redundancy and error handling mechanisms that guarantee the reliable message processing even at the time of failures.
• Decoupled Architecture: it will be a perfect choice for decoupling applications. It allows for independent and synchronous operations enhancing flexibility and scalability.

When to Use Amazon SNS and Amazon SQS Together?

When we consider to use both amazon SNS and Amazon SQS, it is important to understand their complementary roles for building strong decoupled systems. SNS will be ideal for broadcasting messages to multiple subscribers instantly making it as a perfect choice for push notifications, even-driven architectures. On the other hand SQS act as a buffer between message producers and consumers ensuring reliable message delivery and providing asynchronous processing.

• Try to use SNS to broadcast the message to multiple subscribers or endpoints concurrently.
• Use SQS for using enhanced capabilities in decoupled systems for ensuring message durability and reliable processing.
• Utilize SN sto trigger SQS queues, enabling asynchronous processing and handling spikes in message volume efficiency.

How To Choose Between AWS SNS And AWS SQS?

Selecting between Amazon SNS and SQS requires you to make a decision regarding the management of your messages. Amazon SNS functions as a broadcast system, making it ideal for quickly alerting a sizable audience to significant updates. As an alternative, Amazon SQS serves as a message queue, delivering data to various application components in an orderly and independent manner. Amazon SNS is the best option if instantaneous broadcasting to a large audience is your top priority. But if you would rather have a system that thoughtfully distributes messages to different areas of your application in a structured fashion, Amazon SQS is the best option.
In short, it comes down to whether you need to handle messages within your application in an organised manner (SQS) or make large announcements quickly (SNS).

Pros And Cons Of AWS SNS

Pros Of AWS SNS

• Perfect for situations where sending an instant message to one or more recipients is necessary (ex: push notifications).
• Provides real-time message delivery via a push mechanism.
• It is appropriate for situations where the number of subscribers is increasing because it scales with the number of subscribers.

Cons Of AWS SNS

• Because messages are not saved for later retrieval, there is no message persistence.
• AWS SNS charges per message that effects in the cost increase when the message volumes are more.
• AWS SNS doesn’t support delayed message delivery which effects in precising the timing of message delivery.
• SNS comes with limited customization of delivery retries for the messages.

Pros And Cons Of AWS SQS

Pros Of AWS SQS

• Suitable for situations in which various components of a system must function separately (such as load balancing and task offloading).
• Supports a pull mechanism so users can get messages whenever it’s convenient for them.
• Message persistence is offered until it is explicitly removed or fully processed.

Cons Of AWS SQS

• If a message delivery attempt is unsuccessful, consumers are in responsible for handling retries.
• AWS SQS has limit on Message size, Its maximum limit is 256KB per message which is challenging when dealing with larger payloads.
• SQS follows FIFO (Frist-In-First-Out) option, ensuring strict message ordering which increase the complexity and impact on overall system performance.

Pricing of Amazon SNS And Amazon SQS

The following table discuss the pricing of Amazon SNS and Amazon SQS:

Aspect	Amazon SNS	Amazon SQS
Pricing Model	It follows Pay-as-you-go Model	It follows Pay-as-you-go Model
Message Size	It charges $0.50 per million requests and additional charges on protocol type usage eg: HTTP, email, SMS	It charges $0.40 per million requests and after additional charges for data transfer based on region.
Free Tier	For the first 1 million Amazon SNS requests per month it offers as free	For the first 1million Amazon SNS requests per month
Message Retention	N/A	N/A
FIFO Support	It is not applicable to this service	It applies additional charges for FIFO queues

Use Cases of Amazon SNS and Amazon SQS

Amazon SNS Use Cases

The following are the use cases of Amazon SNS:

• Push Notifications: It is useful for delivery notifications for multiple subscribers simultaneously such as mobile devices or email addresses ensuring timely communication with end-users.
• Even-Driven Architecture: It is used in broadcasting events or updates in real-time for multiple consumers. It facilitates the decoupled communication between the microservices or distributed systems.
• Fan-Out Scenarios: It distributes the messages to multiple end-points, facilitating fan-out architectures where on message triggers multiple downstream processes or services.

Amazon SQS Use Cases

The following are the use cases of Amazon SQS:

• Workload Decoupling: It is used wit decouple components as a message queue, allowing the producers to send messages without any waiting for consumers to process them immediately.
• Batch Processing: It facilitates the batch processing of messages by storing them in SQS queues unit the consumers are ready to retrieve those messages and process them.
• Fault Tolerance: It ensure the reliable message delivery and fayult tolerance by using the SQS as buffer for storing the messages the until they are successfully processes. It will help even in the event of system failures or temporary unavailability raise for consumers.

Conclusion

In Conclusion, there are differences between the functions of AWS SNS and AWS SQS when it comes to message management in a system. SNS is the best option if you need to easily broadcast messages to different parts of your system. It guarantees that messages are sent to several subscribers immediately without requiring them to actively fetch them. Conversely, SQS is the answer if you need a more regulated and autonomous processing method. It facilitates efficient handling and scalability by allowing components to operate independently by pulling messages at their own speed. Select SNS for a more extensive message distribution and SQS for an asynchronous, more customised communication setup.

Amazon SNS And SQS – FAQs

How AWS SNS Able To Handle The Message Deivery To Multiple Subscribers?

AWS SNS works on the pub-sub(Publisher-Subscriber) model so it enables the single message to be delivered instantly to multiple subscribers without any individual configuration on each consumer side.

Is AWS SNS Deliver Messages To Mobile Devices Running On Different OS?

Yes, With the help of AWS SNS you can send push notifications to both Android and iOS devices.

Which Channels Does AWS SNS Supports For Message Delivery?

AWS SNS supports emails, SMS, push -notifications, HTTP/HTTPS end points and also provide integration with different AWS services like AWS SQS etc.

How Does AWS SQS Ensures The Message Ordering?

AWS SQS functions on the FIFO(First-In First-Out) principle that ensures the message ordering.

Can I Prioritize Certain Messages Over Others In AWS SQS?

Message prioritisation is not supported by SQS by default. Nonetheless, you can use multiple queues with varying processing priorities to implement your own prioritisation logic.

Can We Use AWS SQS And AWS SNS Together In A Single System?

Yes, to build dependable and scalable distributed systems, AWS SNS and SQS are frequently used in combination.

When other alternatives are out of SNS and SQS?

Apache kafka, Rabbit MQ, Active MQ are the other alternatives to AWS SNS and SQS.

Is SQS Push or Pull?

SQS works on Pull based mechanism

Is SNS Push or Pull?

Amazon SNS works on pull based mechanism

Can I Use SNS for Push Notifications?

Yes, Amazon SNS can be used for pushing notifications.

Why use SNS and SQS Together?

On using SNS and SQS together provides the effective scalability, decoupled messaging for fault-tolerant systems.