Exam DP-420 topic 1 question 10 discussion

Actual exam question from Microsoft's DP-420

Question #: 10
Topic #: 1

HOTSPOT -
You have a container in an Azure Cosmos DB Core (SQL) API account.
You need to use the Azure Cosmos DB SDK to replace a document by using optimistic concurrency.
What should you include in the code? To answer, select the appropriate options in the answer area.
NOTE: Each correct selection is worth one point.
Hot Area:

Show Suggested Answer

Suggested Answer:

Box 1: ConsistencyLevel -
The ItemRequestOptions Class ConsistencyLevel property gets or sets the consistency level required for the request in the Azure Cosmos DB service.
Azure Cosmos DB offers 5 different consistency levels. Strong, Bounded Staleness, Session, Consistent Prefix and Eventual - in order of strongest to weakest consistency.

Box 2: _etag -
The ItemRequestOptions class helped us implement optimistic concurrency by specifying that we wanted the SDK to use the If-Match header to allow the server to decide whether a resource should be updated. The If-Match value is the ETag value to be checked against. If the ETag value matches the server ETag value, the resource is updated.
Reference:
https://docs.microsoft.com/en-us/dotnet/api/microsoft.azure.cosmos.itemrequestoptions https://cosmosdb.github.io/labs/dotnet/labs/10-concurrency-control.html

by AT96 at May 9, 2022, 3:02 a.m.

Comments

Submit Cancel

AT96

Highly Voted 2 years, 2 months ago

When we then want to send our request to replace a document, we can specify an AccessCondition with the ETag we received when we fetched out our document.

upvoted 23 times

grada

1 year, 12 months ago

This, it's supposed to be either AccessCondition or IfMatchETag directly, consistency levels have nothing to do with optimistic concurrency. https://docs.microsoft.com/en-us/dotnet/api/microsoft.azure.documents.client.requestoptions.accesscondition?view=azure-dotnet#examples

upvoted 3 times

...

b890yc

Most Recent 9 months, 2 weeks ago

The namespace Microsoft.Azure.Documents.Client is deprecated. So the below link refers to old version of programming API. In other words, using AccessCondition is deprecated. https://docs.microsoft.com/en-us/dotnet/api/microsoft.azure.documents.client.requestoptions.accesscondition?view=azure-dotnet#examples The latest namespace is Microsoft.Azure.Cosmos and refer to the following links. https://learn.microsoft.com/en-us/dotnet/api/microsoft.azure.cosmos.container.replaceitemasync https://learn.microsoft.com/en-us/dotnet/api/microsoft.azure.cosmos.itemrequestoptions So the answer will be ConsistencyLevel and _etag.

upvoted 2 times

b890yc

9 months, 2 weeks ago

Apologies, so the answer should be ConsistencyLevel and _id. Consistency level can be mentioned in ItemRequestOptions and _id should be passed to Container.ReplaceItemAsync<T> Method.

upvoted 1 times

...

Garyn

9 months, 2 weeks ago

Please correct the answer. it should AccessCondition, and etag.

upvoted 3 times

...

remz

1 year, 10 months ago

Accesscondition ETAG

upvoted 3 times

...