Which of the following statements is incorrect in relation to Vault Operations in Amazon Glacier?

Your company has been storing a lot of data in Amazon Glacier and has asked for an inventory of what is in there exactly. So you have decided that you need to download a vault inventory.

Which of the following statements is incorrect in relation to Vault Operations in Amazon Glacier?
A . You can use Amazon Simple Notification Service (Amazon SNS) notifications to notify you when the job completes.
B . A vault inventory refers to the list of archives in a vault.
C . You can use Amazon Simple Queue Service (Amazon SQS) notifications to notify you when the job completes.
D . Downloading a vault inventory is an asynchronous operation.

Answer: C

Explanation:

Amazon Glacier supports various vault operations.

A vault inventory refers to the list of archives in a vault. For each archive in the list, the inventory provides archive information such as archive ID, creation date, and size. Amazon Glacier updates the vault inventory approximately once a day, starting on the day the first archive is uploaded to the vault. A vault inventory must exist for you to be able to download it.

Downloading a vault inventory is an asynchronous operation. You must first initiate a job to download the inventory. After receiving the job request, Amazon Glacier prepares your inventory for download. After the job completes, you can download the inventory data.

Given the asynchronous nature of the job, you can use Amazon Simple Notification Service (Amazon SNS) notifications to notify you when the job completes. You can specify an Amazon SNS topic for each individual job request or configure your vault to send a notification when specific vault events occur.

Amazon Glacier prepares an inventory for each vault periodically, every 24 hours. If there have been no archive additions or deletions to the vault since the last inventory, the inventory date is not updated. When you initiate a job for a vault inventory, Amazon Glacier returns the last inventory it generated, which is a point-in-time snapshot and not real-time data. You might not find it useful to retrieve vault inventory for each archive upload.

However, suppose you maintain a database on the client-side associating metadata about the archives you upload to Amazon Glacier. Then, you might find the vault inventory useful to reconcile information in your database with the actual vault inventory.

Reference: http://docs.aws.amazon.com/amazonglacier/latest/dev/working-with-vaults.html