Examkin

Question

Difficulty: HardDesign Storage and Non-Relational Data HA and DR

VeloStream Telematics is designing a disaster recovery solution for its vehicle telemetry platform. The platform continuously writes unstructured metrics to a General Purpose v2 storage account in the East US region.

The architecture team defines the following disaster recovery requirements:
- During an outage in East US, the telemetry data must remain available for read-only analytical queries in a secondary region with a Recovery Time Objective (RTO) of less than 1515 minutes.
- To avoid unnecessary data loss due to replication lag, a write failover to the secondary region must only be initiated if the primary region outage is expected to exceed 44 hours.
- The solution must minimize overall storage costs.

Which configuration and failover strategy should you recommend?

  1. Configure the storage account with Read-Access Geo-Redundant Storage (RA-GRS). In the event of a primary region outage, immediately configure the analytics applications to read from the secondary endpoint. If the outage is confirmed to exceed 44 hours, initiate a customer-managed failover to make the secondary region the primary write endpoint.Answer
  2. B
    Configure the storage account with Geo-Redundant Storage (GRS). In the event of a primary region outage, configure the analytics applications to read from the secondary endpoint. If the outage exceeds 44 hours, contact Microsoft Support to trigger a forced failover to the secondary region.
  3. C
    Configure the storage account with Read-Access Geo-Redundant Storage (RA-GRS). In the event of a primary region outage, immediately configure the ingestion client to write to the secondary endpoint to prevent write failures, without initiating a customer-managed failover.
  4. D
    Configure the storage account with Zone-Redundant Storage (ZRS). In the event of a primary region outage, Azure will automatically redirect both read and write requests to a secondary region within the same geography within 1515 minutes.

Answer

Configure the storage account with Read-Access Geo-Redundant Storage (RA-GRS), redirecting read queries to the secondary endpoint during a primary outage, and initiating a customer-managed failover to the secondary region only if the outage exceeds 4 hours.
The correct option recommends configuring the storage account with Read-Access Geo-Redundant Storage (RA-GRS). RA-GRS replicates your data to a secondary region and provides a read-only endpoint. During an East US outage, analytical applications can read from this secondary endpoint immediately without triggering a failover, satisfying the 15-minute read RTO. If the outage is confirmed to exceed 4 hours, a customer-managed failover can be executed to promote the secondary region to the primary endpoint, which enables write operations by changing the storage account type to Locally Redundant Storage (LRS).

Step-by-Step Solution

1
Analyze read RTO requirement during a primary region outage.
Since read operations must be restored within 15 minutes of a primary outage, and write failover must not be triggered unless the outage lasts more than 4 hours, the data replication model must allow direct read access to the secondary region without triggering a failover.
This rules out standard Geo-Redundant Storage (GRS), which requires a failover before the secondary endpoint is readable.
2
Evaluate write capabilities of the secondary endpoint under normal and disaster recovery states.
Read-Access Geo-Redundant Storage (RA-GRS) provides read-only access to the secondary endpoint. It does not accept write operations directly. To restore write capabilities, a customer-managed failover must be initiated, which converts the storage account to Locally Redundant Storage (LRS) in the secondary region.
This rules out active-active architectures or direct writes to the secondary endpoint of RA-GRS without failover.
3
Evaluate the regional resilience capabilities of Zone-Redundant Storage (ZRS).
ZRS only replicates data synchronously across three availability zones within the primary region. It does not provide redundancy in a secondary region, failing the regional disaster recovery requirements.
This rules out ZRS as a regional disaster recovery solution.

Key Concept

Read-Access Geo-Redundant Storage (RA-GRS) provides read-only access to a secondary region without initiating a failover. To enable write operations on the secondary region during a primary outage, a customer-managed failover must be triggered, which changes the replication setting to LRS in the secondary region.
Rate this question

Topics

Design Storage and Non-Relational Data HA and DR

More questions from this topic