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Timed-mode set 3: AWS Lambda in VPC – No valid choice
updated 2 weeks, 6 days ago
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The answer to the attached question seems to rely on the outdated behaviour of Lambda in VPC.
1. The ENI associated with a Lambda function in VPC is created when the Lambda function is created. Therefore, Lambda function creation will fail if a “VPC does not have sufficient subnet ENIs or subnet IPs”. This means that the second option cannot be correct.
2. All invocations of Lambda in VPC use the same ENIs. Also, I do not think every Lambda function invocation is associated with a unique IP address because an ENI supports a limited number of IP addresses. Therefore, an invocation cannot fail because “a subnet runs out of available IP addresses”.
I do not think that any of the options is a possible solution. The given explanation does not even support the solution.
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Hello Mogomotsi,
Thank you for your insightful feedback regarding the question. After reviewing the details, it does appear that the scenario and options rely on outdated behavior related to Lambda functions in VPCs.
As per the latest AWS documentation, the Elastic Network Interface (ENI) associated with a Lambda function is created when the function itself is created rather than during each invocation. This means that errors related to subnet ENI or IP exhaustion during invocation are no longer valid concerns.
Once an ENI is created, it is reused for all subsequent invocations of the Lambda function, which means that issues related to IP address exhaustion at the time of invocation would not occur unless the function configuration changes significantly. Additionally, if the number of connections exceeds this limit, Lambda automatically scales the number of ENIs based on network traffic and concurrency requirements.
We will update the item to reflect the current Lambda VPC functionality. Thank you again for helping us improve the accuracy of our content. If you have any further suggestions or questions, please feel free to share them!
Regards,
Nikee @ Tutorials Dojo
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