Cloud Integration

Simple Queue Service.
Fully managed service used to decouple applications.
Low Latency.
Scales from 1 msg per second to 10,000s per second.
Default retention of messages: 4 days, max of 14 days.
No limit to how many msgs can be in the queue.
Messages are deleted after they're read by consumers.
Consumers share the work to read msgs & scale horizontally.
FIFO Queue
- First In First Out (ordering of messages.)
- Messages are processed in order by the consumer.

Kinesis = real-time big data streaming.
Managed service to collect, process, and analyze real-time streaming data at any scale.
Some handy things to know that won't be in the exam:
- Kinesis Data Streams: low latency streaming to ingest data at scale from hundreds of thousands of sources.
- Kinesis Data Firehose: load streams into S3, Redshift, ElasticSearch, etc...
- Kinesis Data Analytics: perform real-time analytics on streams using SQL.
- Kinesis Video Streams: monitor real-time video streams for analytics or ML.

For sending one message to many receivers.
The "event publishers" sends one message to one SNS topic.
As many "event subscribers" as we want can listen to the SNS topic for notifications.
Each subscriber will get all the messages.
Up to 12,500,000 subscriptions per topic, 100,000 topics limit.
Subscribers can be anything from a Lambda to mobile device.

SQS and SNS are cloud native services: proprietary protocols from AWS.
Traditional applications running from on-premises may use open protocols like MQTT, AMQP, etc.
When migrating to the cloud, rather than re-engineering the application to use SQS or SNS, we can use Amazon MQ.
It's a managed messaged broker service for RabbitMQ and ActiveMQ.
It doesn't scale as much as SQS/SNS.
It runs on servers, can run in Multi-AZ with failover.
It has both queue feature (SQS) and topic features (SNS).

SQS:
- Queue service in AWS
- Multiple Producers, messages are kept up to 14 days
- Multiple Consumers share the read and delete messages when done
- Used to decouple applications in AWS
SNS:
- Notification service in AWS
- Subscribers: Email, Lambda, SQS, HTTP, Mobile…
- Multiple Subscribers, send all messages to all of them
- No message retention
Kinesis: real-time data streaming, persistence and analysis
Amazon MQ: managed message broker for ActiveMQ and RabbitMQ in the cloud (MQTT, AMQP.. protocols)