All About AWS SNS

SNS is Fast, Reliable, flexible,fully managed,Simple push Notification Service Provided by AWS . It allows users to fan out messages in real time with no time delay.
We see SNS service Example in day to day life .
In simple terms we get messages on our email or phone regarding Flipkart,Amazon or Banking Service .

Components of SNS :-

1. Publisher :- Publisher is that component that publishes messages . Anything that can publish or send message is a publisher .
eg. Microservices
2. SNS topic :- It is a logical access point and communication channel. We create a Topic on our AWS account on which publisher send messages . Subscribers that subsribe to that topic will get message immediately
send to that Topic .
3. Subscribers :-Subscribers such as Webservers, email address,Amazon SQS queue, AWS Lambda, HTTP/HTTPS receive messages from
SNS topic by one of the supported protocols .

How SNS works :-

Let’s understnad it by a use case . I need to send messages when there is increase or decrease in interest rate of ICICI Bank .(very common example)
I will create a topic named as Banking-Interest( as per own choice) .After that I will subscribe all bank users on that topic(whether by mail id or
by phone number).

If there will be any change in interest rate that message will be pushed to topic and hence will send to all users on their mail id or phone number .

Some Small but Important Points:-
1. When a topic is created an ARN is assigned to that topic By AWS . We can relate to ARN like an id provided to topic by AWS.
2. It is called fully managed as we don’t have to manage it .It is managed by AWS itself .
3. SNS service is used majorly to send messges in bulk .
4. It is called Reliable as there will be 3 copies of each messages are stored in multiple AZ in same region .
5. Each topic should have different name as per AWS account.