Soru

Zorluk: ZorModernizing Workloads with Serverless Architectures (Lambda and API Gateway)

A logistics and supply chain enterprise is modernizing its fleet dispatching and tracking application by migrating its core API to a serverless architecture on AWS. The API must handle highly bursty and unpredictable transaction volumes, spiking up to 15,00015,000 requests per second. The backend logic runs on AWS Lambda and reads from an Amazon Aurora PostgreSQL database cluster deployed in a private VPC subnet. To protect the database from connection exhaustion, an Amazon RDS Proxy has been deployed. The API Gateway endpoint is private, accessible only from the company's corporate offices through an existing AWS Direct Connect connection. The architect must ensure that:

1. Bursty traffic spikes do not exhaust the regional Lambda concurrency limit, which would throttle other critical serverless workloads in the same AWS account.
2. The database credentials, stored in AWS Secrets Manager, are rotated automatically every 3030 days and encrypted using a KMS key that can be shared with a monitoring tool in a separate security audit account.
3. The serverless compute layer remains highly available and resilient to Availability Zone failures.

Which combination of actions should the Solutions Architect implement to meet these requirements? (Select TWO.)

  1. Configure a reserved concurrency limit on the Lambda function to control the maximum concurrent executions, preventing the function from consuming the entire regional account concurrency pool.Cevap
  2. Store the database credentials in AWS Secrets Manager, enable automatic rotation, and encrypt the secret using a Customer Managed Key (CMK), configuring the KMS key policy to permit decryption by both the Lambda execution role and the cross-account security audit role.Cevap
  3. C
    Configure provisioned concurrency on the Lambda function to handle the peak request spikes, allowing the function to scale dynamically while utilizing the default regional concurrency pool without restriction.
  4. D
    Store the database credentials in AWS Secrets Manager, enable automatic rotation, and encrypt the secret using the default AWS-managed KMS key (aws/secretsmanager), and add a cross-account permission statement to the default KMS key policy.
  5. E
    Deploy the Lambda function in a single private subnet within one Availability Zone, routing all database-bound traffic through a single NAT Gateway to simplify security group rules on the Amazon Aurora cluster.

Cevap

Configure a reserved concurrency limit on the Lambda function and use a Customer Managed Key (CMK) for encrypting the database credentials in Secrets Manager with cross-account access.
Configuring a reserved concurrency limit sets a ceiling on the Lambda function's parallel executions, which isolates its resource usage and protects other regional serverless applications from throttling. Storing the credentials in Secrets Manager and using a Customer Managed Key (CMK) allows full customization of the KMS key policy, making it possible to grant cross-account decryption rights to the audit monitoring tool.

Adım Adım Çözüm

1
Analyze the impact of high-volume bursty traffic on Lambda concurrency limits.
Unconstrained Lambda functions can scale rapidly and consume the entire account's regional concurrency pool.
Applying reserved concurrency guarantees a maximum execution limit for the specific function and prevents it from starving other workloads.
2
Evaluate KMS encryption options for Secrets Manager cross-account access.
AWS-managed KMS keys cannot have their key policies modified to delegate cross-account access.
A Customer Managed Key (CMK) must be used so that its key policy can be updated to trust the external security audit account's role.
3
Assess high availability and networking practices for serverless integrations.
Lambda functions must be mapped to multiple subnets across different Availability Zones with redundant NAT Gateways to avoid a single point of failure.
This guarantees execution resiliency in the event of an Availability Zone outage.

Anahtar Kavram

Serverless architectures require concurrency controls to protect shared account resources, and cross-account access to encrypted data requires Customer Managed Keys (CMKs).
Bu soruyu puanla