Exam AZ-204 topic 3 question 30 discussion

I think it should be: - ETag - server returns this tag for a resource to ensure we operate on the same version of the resource in subsequent API calls - If-Match - update is processed by the server only if the ETag provided matches the latest resource version ETag The reason for that is we want to make sure we update the latest version of a resource: "Update operations must use the latest data changes when writing" So, when using Last-Modified with If-Modified-Since, the operation executes only when another client modifies the resource between our READ and WRITE operations. If we wanted to use Last-Modified instead, we would need If-Unmodified-Since instead.

I referred to the documentation also and I cannot convince my mind I care enough to even understand this because there is no chance I will ever have to know these options in details unless I have to use it. Who reads and understands all these information when this is available as documentation and with Microsoft documentation it is all about trial and error and hoping for the best

Based on the scenario where you need to implement update operations for a web application accessing data in a zone-redundant BlockBlobStorage storage account, the application must ensure it uses the latest data by checking whether the data has changed since it was last read. Here are the appropriate choices: 1. HTTP Header value: ETag Reason: The ETag (Entity Tag) is a unique identifier assigned to a specific version of a resource. It is used to determine if the data has changed since the last request. When you read the data, you get the ETag, and when performing update operations, you can compare the ETag to ensure you are working with the latest version of the data. 2. Conditional header: If-Match Reason: The If-Match header is used to perform operations only if the ETag of the resource matches the one specified in the request. This ensures that updates happen only if the resource hasn't been modified since it was last read, preventing overwrites of more recent updates.

Got examn 28/09/23

both are wrong in given solution. Correct anser - etag and If-match

It's ETag and If-Match. The ETag (Entity Tag) is an HTTP header that represents a unique identifier for a version of the resource. When sending an update request, you can include the If-Match header with the ETag value of the data you previously read. If the current ETag of the resource matches the provided ETag, it means the data hasn't changed.

Correct answer

It is Etag and If-Match check this page https://learn.microsoft.com/en-us/rest/api/storageservices/specifying-conditional-headers-for-blob-service-operations for conditional header "If-Match" - We can specify ETag value. Specify this header to perform the operation only if the resource's ETag matches the value specified.

Etag and if-match ChatGPT

Since we also need the update to work which is a PUT operation the correct answer is ETag/If-Match

ETag If-Match There are 2 possible options to validate an update against unwanted changes: - ETag + If-Match - Last-Modified + If-Unmodified-Since The second option is not available here, so it must be the first one. Besides, even if it was available, it would still be better to check ETag, because Last-Modified is weaker (it has only 1-second resolution, so it does not detect 2 changes within 1 second, so you cannot ensure you have the latest version) and I guess the zone-redundancy may also play some role in how Last-Modified is handled.

For those who have taken AZ-204 test, should I trust ExamTopics answers or the Community's answers?

Etag, If-Match are correct answers as per MS docs Optimistic concurrency: An application performing an update will, as part of its update, determine whether the data has changed since the application last read that data. For example, if two users viewing a wiki page make an update to that page, then the wiki platform must ensure that the second update does not overwrite the first update. It must also ensure that both users understand whether their update was successful. This strategy is most often used in web applications. https://learn.microsoft.com/en-us/azure/storage/blobs/concurrency-manage?tabs=dotnet

I think it should be E-tag and if-none-match. See the following source on how e-tag works: https://en.wikipedia.org/wiki/HTTP_ETag

I think the answer is correct. The question is asking explicitly if "data changed since the application last read the data", so we must evaluate against the date, hence If-Modified-Since.

Answer is correct - in my opinion. - ETag - The ETag (or entity tag) HTTP response header is an identifier for a specific version of a resource. (Version!) - Last-Modified - The Last-Modified response HTTP header contains a date and time when the origin server believes the resource was last modified. (Date and Time!) (Source: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers) In Question: The application must determine whether the data has changed since the application last read the data. My understanding: We are working on dates, not versions! So, Last-Modified and If-Modified-Since are better options. PS: I honestly have no idea why I need to know this for Azure Certification Exam :((

Got this question in the exam 27/11/2022, anyone, please mention the correct answer and explain