What sort of updates do ELB properties support (for CloudFormation)?

Question

Question: What type of updates do each ELB property support?

I'm reading through the ELB CF docs:

AWS::ElasticLoadBalancing::LoadBalancer http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-ec2-elb.html

On the page it states "This type supports updates".

The only property that goes into detail is this one:

SecurityGroups Required: No.

Type: A list of security groups assigned to your load balancer within your virtual private cloud (VPC).

Update requires: no interruption

No other properties mention what type of update they trigger.

Am I missing something in the documentation? Is there a default update action for the other properties?

Answer 1

As per the response from AlastairC@AWS on my forum post:

https://forums.aws.amazon.com/thread.jspa?threadID=139722

Updating the following properties triggers a replacement of an ELB. All other properties will not trigger replacement:

• AvailabilityZones
• HealthCheck
• Scheme
• Subnets

The AvailabilityZones/Subnets changes make sense.

I can even live with the Scheme changes.

I'm not thrilled with the fact that if you change any HealthCheck values this will cause a new ELB to be created (and thus require DNS changes).

At least we've got an answer!

Also, they mentioned the AWS docs will be updated:

Thanks so much for bringing this to our attention! We are working on a fix to our documentation and will post an update to this thread once the fix is rolled out.