What should a solutions architect recommend to resolve this issue?
Add a DynamoDB Accelerator (DAX) cluster in front of the DynamoDB database.
Add an Amazon API Gateway API in front of the web application that accepts the appointment requests.
Add an Amazon CloudFront distribution. Set the origin as the web application that accepts the appointment requests.
Add an Auto Scaling group for the application that sends meeting invitations. Configure the Auto Scaling group to scale based on the depth of the SQS queue.
Explanations:
Adding a DynamoDB Accelerator (DAX) could improve the read performance of the DynamoDB database, but it does not address the issue of delayed meeting invitations since the bottleneck is likely with the processing of SQS messages rather than database reads.
While adding an Amazon API Gateway in front of the web application could provide better management and security, it would not directly solve the problem of delays in sending meeting invitations, as the core issue lies in the processing capacity of the application handling the invitations.
Adding an Amazon CloudFront distribution would help with content delivery for static assets but does not solve the problem of delayed processing for meeting invitations. The delays are related to the processing of messages in the SQS queue, not the delivery of static content.
Adding an Auto Scaling group for the application that sends meeting invitations would allow the application to scale based on the depth of the SQS queue. This would enable the system to handle increased loads more effectively, ensuring timely processing of appointment requests and sending meeting invitations.
I classify that the answer is:
Add an Auto Scaling group for the application that sends meeting invitations. Configure the Auto Scaling group to scale based on the depth of the SQS queue.