3.1, 3.2 - Azure Storage Accounts, Cosmos DB and Blob Storage

Question 1

What is the difference between Managed Storage and Storage Account when it comes to pricing?

Answer 1

Managed Storage is provisioned to a size and you pay for that size whether you use it at all or not

You’re billed for Azure Storage based on your storage account usage. All objects in a storage account are billed together as a group

Question 2

What is the downside for setting “strong consistency” on a Cosmos DB database with a lot of replicas?

Answer 2

There might be delays in reading data as it waits for the data to be replicated

Question 3

What is one major advantage that Cosmos DB offers over a Storage Account table storage?

Answer 3

Sub 10ms latency guaranteed

Question 4

What is the weakest form of data consistency

Answer 4

Eventual - There’s no ordering guarantee for reads. A client may get the values which are older than the ones it had seen before, over time

Question 5

Which data consistency offers a linearizability guarantee?

Answer 5

Strong

Question 6

The reads might lag behind writes by at most “K” versions (that is, “updates”) of an item or by “T” time interval - which data consistency is this?

Answer 6

Bounded Staleness

Question 7

Which consistency level guarantees that read never see out-of-order writes?

Answer 7

Consistent Prefix

Question 8

What command you would use to transfer blobs between containers and storage accounts

Answer 8

az storage blob copy

Question 9

With Cosmos DB, you do not pay for CPU, IOPS, or memory. What two elements are used to determine pricing?

Answer 9

Cosmos DB has the concept of Provisioned RU/s which gives you up to a certain requests per second. If you need more, you need to upgrade. It also charges for storage

• Provisioned Request Units per second
• Storage used in GB