Beanstalk

Question 1

What is elastic beanstalk?

Answer 1

It is a way to easily deploy well known architectures

Question 2

What are the two possible environments on beanstalk?

Answer 2

Web server - ELB + ASG + EC2
Worker - SQS + ASG + EC2 - scale based on number of SQS messages

Question 3

What are elastic beanstalk deployment modes?

Answer 3

All at once
* destroy all instances and raise new ones
Rolling
* creates new instances, destroying old ones, based on a bucket size. When they are healthy, move to the next bucket. Stops when all instances are running the new version.
Rolling with additional batches
* creates new instances, without destroying the old ones, creating additional instances temporarily (increases cost)
Immutable
* Creates a new ASG with the new version, running one instance
* when the new instance is ok, merge with the old one
* kills new ASG
* kills older version
* fast rollback, since is only kill the new ASG
Blue green
* create a new env (green) and send part of the traffic to green env to perform tests
* when green is ok, shutdown blue
Traffic splitting (canary testing)
* New app version is deployed to a temp ASG with same capacity
* Small % of traffic is sent to temp ASG for some time
* ALB performs the traffic splitting

Question 4

What if you want to add resources on beanstalk?

Answer 4

If you want to add resources to Elastic Beanstalk like RDS, ElastiCache, you can create extensions.

Question 5

What if you created Elastic beanstalk env and want to change ELB type?

Answer 5

It is not possible, you will need to create a new env, deploy your app to this env and perform a CNAME swap or route 53 update.

Question 6

Why creating RDS on elastic beanstalk is not a good practice?

Answer 6

The database will be tied to beanstalk lifecycle. It will be destroyed with beanstalk. It is best to create RDS separately and use the connection string