Cloud Integration

Section Introduction

• When we start deploying multiple applications, they will inevitably need to communicate with one another
• There are two patterns of application communication
  1. Synchronous communications (application to application)
  2. Asynchronous / Event based (application to queue to application)
• Synchronous between applications can be problematic if there are sudden spikes of traffic
• What if you need to suddenly encode 1000 videos but usually it’s 10?
• In that case, it’s better to decouple your applications:
  • using SQS: queue model
  • using SNS: pub/sub model
  • using Kinesis: real-time data streaming model (out of scope for the exam)
• These services can scale independently from our application!

Amazon SQS - Simple Queue Service

• Oldest AWS offering (over 10 years old)
• Fully managed service (~serverless), use to decouple applications
• Allows decoupling of applications by sending and receiving messages asynchronously.
• Supports standard queues (unlimited throughput) and FIFO queues (ordered processing).
• Scales from 1 message per second to 10,000s per second
• Default retention of messages: 4 days, maximum of 14 days
• No limit to how many messages can be in the queue
• Messages are deleted after they’re read by consumers
• Low latency (less than 10 ms on publish and receive)
• Consumers share the work to read messages & scale horizontally

Amazon Kinesis

• Kinesis = real-time big data streaming
• Managed service to collect, process, and analyze real-time streaming data at any scale
• Too detailed for the Cloud Practitioner exam but good to know:
  • 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

Amazon SNS

• What if you want to send one message to many receivers?
• Amazon Simple Notification Service is a notification service provided as part of Amazon Web Services since 2010. It provides a low-cost infrastructure for mass delivery of messages, predominantly to mobile users.
• The “event publishers” only sends message to one SNS topic
• As many “event subscribers” as we want to listen to the SNS topic notifications
• Each subscriber to the topic will get all the messages
• Up to 12,500,000 subscriptions per topic, 100,000 topics limit

Amazon MQ

• SQS, SNS are “cloud-native” services, and they’re using proprietary protocols from AWS.
• Traditional applications running from on-premise may use open protocols such as: MQTT, AMQP, STOMP, Openwire, WSS
• When migrating to the cloud, instead of re-engineering the application to use SQS and SNS, we can use Amazon MQ
• Amazon MQ = managed Apache ActiveMQ
• Amazon MQ doesn’t “scale” as much as SQS / SNS
• Amazon MQ runs on a dedicated machine (not serverless)
• Amazon MQ has both queue feature (~SQS) and topic features (~SNS)

Integration - Summary

• 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 Apache MQ in the cloud (MQTT, AMQP.. protocols)