Unprocessed items handling in DynamoDB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What are unprocessed items in DynamoDB batch operations?

Unprocessed items are those that DynamoDB could not process in a batch write or batch get request due to throttling or internal errors. They need to be retried to ensure all data is handled.

beginner

How does DynamoDB indicate unprocessed items in a batch write response?

DynamoDB returns unprocessed items in the response under the key 'UnprocessedItems'. This contains the items that were not written and should be retried.

intermediate

Why is it important to handle unprocessed items in DynamoDB batch operations?

Because DynamoDB may throttle requests or face temporary issues, unprocessed items ensure you don't lose data. Retrying them guarantees data consistency and completeness.

intermediate

What is a common strategy to handle unprocessed items in DynamoDB batch writes?

A common strategy is to check the 'UnprocessedItems' in the response and retry sending them after a short delay, often using exponential backoff to avoid repeated throttling.

beginner

Can unprocessed items occur in both BatchWriteItem and BatchGetItem operations?

Yes, unprocessed items can occur in both BatchWriteItem and BatchGetItem operations when DynamoDB cannot process all requested items in a single batch.

What does DynamoDB return when some items in a batch write are not processed?

A An error and no data

B A partial success without details

C A success message with all items processed

D A list of unprocessed items under 'UnprocessedItems'

DynamoDB returns the unprocessed items under the 'UnprocessedItems' key so you can retry them.

Why might DynamoDB return unprocessed items in a batch operation?

A Because the table is deleted

B Because the items are invalid

C Due to throttling or internal errors

D Because the request was too small

Unprocessed items usually happen because DynamoDB throttles requests or encounters temporary internal issues.

What is the best practice after receiving unprocessed items from DynamoDB?

A Ignore them

B Retry after a delay, possibly with exponential backoff

C Retry immediately without delay

D Delete the unprocessed items

Retrying after a delay with exponential backoff helps avoid repeated throttling and increases success chances.

In which DynamoDB operations can unprocessed items appear?

A Both BatchWriteItem and BatchGetItem

B Only BatchGetItem

C Only BatchWriteItem

D Only PutItem

Unprocessed items can appear in both batch write and batch get operations.

What happens if you do not handle unprocessed items in DynamoDB batch writes?

A Some data may be lost or not written

B The request fails completely

C DynamoDB automatically retries them forever

D All data is saved anyway

If unprocessed items are ignored, some data may not be saved, causing inconsistency.

Explain what unprocessed items are in DynamoDB batch operations and why you need to handle them.

Think about what happens when DynamoDB can't finish all requests at once.

Describe a simple approach to handle unprocessed items returned by DynamoDB batch write requests.

Consider how to avoid hammering DynamoDB repeatedly.