Readings: Event Driven Architecture
Review, Research, and Discussion
- What’s the difference between a FIFO and a standard queue?
- Standard queues guarantee that a message is delivered at least once and duplicates can be introduced into the queue. FIFO queues ensure a message is delivered exactly once and remains available until a consumer processes and deletes it; duplicates are not introduced into the queue.
-
For further information clicks =>here
- How can the server be assured a message was properly received?
- By using the message Queue.
- What classic design pattern is best represented by event driven programming?
- Event Notification It is the most basic pattern describing event driven programming.
-
For further information clicks =>here
- How do you test an event driven system?
- In an event-driven application architecture, the developer is going to have to do a lot more work. But this work can be reduced by creating an automation process that scaffolds up the unit testing environment. Once the process is automated, it can be shared with each developer in the team to meet their individual needs.
- Higher-level testing will also require using automation to provision the messaging infrastructure. And aggregated logging and distributed tracing need to be part of the messaging infrastructure; otherwise, test practitioners will have no way to observe and measure the results of their efforts. The logging and tracing facilities also will need to accommodate system monitoring as well as application monitoring.
-
For further information clicks =>here
Vocabulary
- FIFO Queue
- FIFO (First-In-First-Out) queues are designed to enhance messaging between applications when the order of operations and events is critical, or where duplicates can’t be tolerated.
-
For further information clicks =>here
- Pub/Sub
- Is an asynchronous messaging service that decouples services that produce events from services that process events.
-
For further information clicks =>here
Preparation
- AWS SNS and SQS
- SNS (Simple Notification Service)
- 
- SNS is a distributed publish-subscribe system. Messages are pushed to subscribers as and when they are sent by publishers to SNS.
- A distributed publish-subscribe system. Messages are pushed to subscribers as and when they are sent by publishers to SNS ,SNS supports several end points such as email, sms, http end point and SQS. If you want unknown number and type of subscribers to receive messages, you need SNS.
- SQS (Simple Queue Service)
- 
- SQS is distributed queuing system. Messages are not pushed to receivers. Receivers have to poll SQS to receive messages.
- SQS is mainly used to decouple applications or integrate applications. Messages can be stored in SQS for short duration of time (max 14 days). SNS distributes several copies of message to several subscribers. For example, lets say you want to replicate data generated by an application to several storage systems. You could use SNS and send this data to multiple subscribers, each replicating the messages it receives to different storage systems (s3, hard disk on your host, database, etc.).
-
- SNS (Simple Notification Service)
| Read | Title | ToGo |
|---|---|---|
| Read: 01 | Pre-Work - Code 401: Advanced Javascript Development |  |
| Read: 02 | Readings: Express | |
| Read: 03 | Readings: Express REST API | |
| Read: 04 | Readings: Data Modeling | |
| Read: 06 | Readings: Authentication | |
| Read: 07 | Reading: Bearer Authorization | |
| Read: 08 | Reading: Access Control (ACL) | |
| Read: 09 | Reading: OAuth 2 | |
| Read: 11 | Readings: Event Driven Applications | |
| Read: 12 | Readings: Socket.io | |
| Read: 13 | Readings: Message Queues | |
| Read: 14 | Readings: Event Driven Architecture | |
| Read: 16 | Readings: AWS: Cloud Servers | |
| Read: 17 | Readings: AWS: S3 and Lambda | |
| Read: 18 | Readings: AWS: API, Dynamo and Lambda | |
| Read: 18 | Readings: AWS: Events | |
| Read: 26 | Reading: Component Based UI | |
| Read: 27 | Reading: Props and State | |
| Read: 28 | Readings: Component Composition | |
| Read: 29 | Readings: Routing | |
| Read: 31 | Reading: Hooks API | |
| Read: 32 | Reading: Custom Hooks | |
| Read: 33 | Reading: Context API | |
| Read: 34 | Reading: <Login /> and <Auth /> |
|
| Read: 36 | Reading: Application State with Redux | |
| Read: 37 | Readings: Redux - Combined Reducers | |
| Read: 38 | Readings: Redux - Asynchronous Actions | |
| Read: 39 | Readings: Redux - Additional Topics | |