env_aws: Disable Retries and set Session cfg #6860
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Previously, Nomad used hand rolled HTTP requests to interact with the EC2 metadata API. Recently however, we switched to using the AWS SDK for this fingerprinting. The default behaviour of the AWS SDK is to perform retries with exponential backoff when a request fails. This is problematic for Nomad, because interacting with the EC2 API is in our client start path. Here we revert to our pre-existing behaviour of not performing retries in the fast path, as if the metadata service is unavailable, it's likely that nomad is not running in AWS.
notnoop
approved these changes
Dec 16, 2019
notnoop
reviewed
Dec 16, 2019
| if err != nil { | ||
| return nil, err | ||
| } | ||
| return ec2metadata.New(session, c), nil |
There was a problem hiding this comment.
Curious, if the session is already configured with the config option, do we still need to pass it to ec2metadata.New?
There was a problem hiding this comment.
I am honestly not quite sure, it's probably safer to pass to both, because the SDK is a little bit messy tbh.
Co-Authored-By: Mahmood Ali <[email protected]>
|
I'm going to lock this pull request because it has been closed for 120 days ⏳. This helps our maintainers find and focus on the active contributions. |
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Previously, Nomad used hand rolled HTTP requests to interact with the
EC2 metadata API. Recently however, we switched to using the AWS SDK for
this fingerprinting.
The default behaviour of the AWS SDK is to perform retries with
exponential backoff when a request fails. This is problematic for Nomad,
because interacting with the EC2 API is in our client start path.
Here we revert to our pre-existing behaviour of not performing retries
in the fast path, as if the metadata service is unavailable, it's likely
that nomad is not running in AWS.
This brings the Nomad agent start time back down from ~20s to ~7s on my
laptop.