[aemous]

Issue #, if available:

#10676

Description of changes:

• Enable the CRT S3 transfer client by default for all remaining EC2 instances. This includes removing the allowlist from internal code and documentation.
• Update outdated unit tests that relied on some EC2 instances not being rolled out yet.
• Update docs to clarify all EC2 families auto-resolve to CRT S3 transfer client by default (barring config settings).

Description of tests:

• Successfully ran all tests and CI (see GitHub Actions).

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[ashovlin]

Fragment "urrently". And should we just remove this list and revise the bullet on L341 to "The host running the AWS CLI is an Amazon EC2 instance "

[aemous]

Will push a fix for the typo.

I kept the list of optimized instance families in the docs for two reasons:

1. The list is referenced later in the docs to determine fallback logic, so it's helpful for customers to know whether their host is considered optimized to understand CLI fallback logic:

The crt transfer client supports the requested transfer. If the host
is not of an instance type that the crt transfer client is optimized
for, the AWS CLI falls back to the classic transfer client when any
of the following are in use:

2. Which hosts are optimized is valuable information for customers. It may guide their decision in choosing a host, for example.

Open to discussion / feedback.

[luigi617]

I feel like this part is confusing. We are rolling out all the EC2 instances, but as we removed the list of instance families, my understanding of this sentence is, crt will be used only for p4d.24xlarge``, p4de.24xlarge``, ....and for all other families we are falling back to classic transfer client.

[aemous]

the AWS CLI falls back to the classic transfer client when any
of the following are in use:

crt will be used only for p4d.24xlarge, ... and for all other families we fall back to classic client when certain config settings are used.

does this help resolve the confusion? do you have suggested alternative wording?

[luigi617]

LGTM