<h1 id="sns-simple-notification-service">SNS (Simple Notification Service)<a aria-hidden="true" class="anchor-heading icon-link" href="#sns-simple-notification-service"></a></h1>
AWS SNS is a fully managed messaging service for decoupling event-driven microservices. 
<ul>
<li>It enables us to send messages reliably between parts of the infrastructure.</li>
</ul>
SNS works via <a href="/notes/NpY4iv9TwpGJODbVesQYe">pub/sub</a> topics to allow services to consume relevant events.
SNS can be set up to send messages to end users via email, SMS, mobile push notifications etc.
SNS uses a robust retry mechanism in cases where downstream targets are unavailable.
<ul>
<li>If it still fails, it will utilize a <a href="/notes/0pUoWXrTC07Z9B1ijwosK">DLQ</a>.</li>
</ul>
SNS does not retain messages so if there are no subscribers for a topic, the message is discarded.
<ul>
<li>comparatively, an [[</li>
</ul>
SNS uses topics to logically separate messages into channels, and your <a href="/notes/OSdV9FvBG3wDbRNLllg0V">Lambda functions</a> interact with these topics.
SNS topics may broadcast to multiple targets (fan-out).
<ul>
<li>An SNS topic can have up to 12,500,000 subscribers, providing highly scalable fan-out capabilities.</li>
</ul>
SNS can be used to parallelize work across Lambda functions or send messages to multiple environments (such as test or development).
<h3 id="vs-eventbridge">vs <a href="/notes/7n3tUhrwbvz8nNu0bTlWz">EventBridge</a><a aria-hidden="true" class="anchor-heading icon-link" href="#vs-eventbridge"></a></h3>
Both can be used to decouple publishers and subscribers, filter messages or events, and provide fan-in or fan-out capabilities.
EventBridge offers two capabilities not in SNS:
<ul>
<li>SaaS integration</li>
<li>Schema registry</li>
</ul>
<hr>
Backlinks
<ul>
<li><a href="/notes/QukN1H4jrogOyBjotZd7U">AWS Services</a></li>
<li><a href="/notes/Skg9BUUhw2xIBmwrkEP4u">Messaging Pattern</a></li>
<li><a href="/notes/Ag4RGxbqigmzcZAUS9FRv">Lambda Function</a></li>
<li><a href="/notes/0pUoWXrTC07Z9B1ijwosK">Dead Letter Queue</a></li>
</ul>

SNS (Simple Notification Service)

tech

This Dendron vault of tech knowledge is organized according to domains and their sub-domains, along with specific implementation of those domains.

For instance, Git itself is a domain. Sub-domains of Git would include topics like `commit`,
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The goal of the wiki is to present data in a manner that is from the perspective
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and hasn't done them in a while, they should be able to query
`postgres.functions` to see basic implementations, as well as common patterns
that have been employed in the past.

This wiki has been written with myself in mind. While learning each of these
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insights as they arose. I have refrained from capturing information that I
considered obvious or otherwise non-beneficial to my own understanding.

As a result, I have allowed myself to use potentially arcane concepts to help
explain others. For example, in my note on [[unit testing|testing.method.unit]],
I have made reference to the [[microservices|general.arch.microservice]] note.
The ability to analogize between different concepts captured in different notes
allows an opportunity to build strong generalized understandings. Given that
you'd have to understand microservices to be able to draw that same parallel
that I've already drawn, these links won't work for everyone. Since these notes
are written for myself, I have been fine with taking these liberties and leaning
on them heavily.

What I hope to gain from this wiki is the ability to step away from any
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vague sounding, and really depends on the domain along with the ends I am
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To achieve this, the system should be steadfast to:
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This Dendron notebook is the sister vault to the general [Second Brain](https://tech.kyletycholiz.com).

## Tags
Throughout the garden, I have made use of tags, which give semantic meaning to the pieces of information.

- `ex.` - Denotes an *example* of the preceding piece of information
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## Resources
### UE (Unexamined) Resources
Often, I come across sources of information that I believe to be high-quality. They may be recommendations or found in some other way. No matter their origin, I may be in a position where I don't have the time to fully examine them (and properly extract notes), or I may not require the information at that moment in time. In cases like these, I will add reference to a section of the note called **UE Resources**. The idea is that in the future when I am ready to examine them, I have a list of resources that I can start with. This is an alternative strategy to compiling browser bookmarks, which I've found can quickly become untenable.

### E (Examined) Resources
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### Resources
This heading is for inexhaustible resources. 
- A prime example would be a quality website that continually posts articles.  - Another example would be a tool, such as software that measures frequencies in a room to help acoustically treat it.


SNS (Simple Notification Service)

vs EventBridge