CRC Errors in Dynamodb

In most/all browsers that support CORS, the JavaScript runtime cannot access the x-amz-crc32 header since the service doesn't explicitly expose it, which means that the CRC32 check is not performed in these environments. However, in some environments, the JavaScript environment can access all headers, including x-amz-crc32, because CORS are not enforced. This is why the check occurs in a some environments, but not in a browser.

Another thing to consider is that DynamoDB will gzip the response payload if it exceeds a certain threshold, but it calculates the CRC32 checksum after the payload is gzipped. By the time the payload reaches the JavaScript runtime, it is no longer gzipped, so the calculated checksum won't match. This behavior can cause some checksums to pass and others to fail, depending on the size of the response body.

One possible solution is to disable gzip, but this would result in more data being transferred over the wire. It might be useful to add a configuration option for disabling gzip when payload sizes are not a concern. In the meantime, disabling the CRC32 check should resolve the issue.

import AWS from 'aws-sdk';

AWS.config.update({
  dynamoDbCrc32: false
});

// rest of code 

I am not using an API but accessing Dynamodb via web browser.

How can I make your suggested CrC32 check update using for e.g. python?