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Difficulty: MediumAzure Cosmos DB and NoSQL Solutions

You are designing the data storage solution for a global micro-mobility fleet management system that tracks 150,000150,000 active electric scooters. The scooters report status updates, including battery level and GPS coordinates, every 1010 seconds. The read-to-write ratio is 1:101:10 (write-heavy). The system must support multi-region write replication across East US, West Europe, and Southeast Asia to guarantee write latency below 10 ms10\text{ ms} globally. The solution must survive a complete regional outage without data loss or downtime. Which design configuration meets these requirements while preventing hot partitions and ensuring regional disaster resilience?

  1. A
    Configure Azure Cosmos DB with multi-region writes enabled across the target regions, and set the partition key to the scooter's operating status to group the telemetry data.
  2. B
    Configure Azure Cosmos DB as a single-region deployment utilizing Locally Redundant Storage (LRS) to optimize database throughput, and rely on daily database backups to survive regional outages.
  3. Configure Azure Cosmos DB with multi-region writes enabled across East US, West Europe, and Southeast Asia, and set the partition key to the unique scooter identifier.Answer
  4. D
    Configure Azure Cosmos DB with multi-region writes enabled, set the partition key to the unique scooter identifier, and distribute access tokens to the fleet using Shared Access Signatures (SAS) with a five-year validity duration directly embedded in each device's configuration.

Answer

Configure Azure Cosmos DB with multi-region writes enabled across the target regions, using the unique scooter identifier as the partition key.
Configuring Azure Cosmos DB with multi-region writes enables active-active writes in East US, West Europe, and Southeast Asia, allowing the write-heavy client applications to achieve sub-10ms latency. The unique scooter identifier acts as a high-cardinality partition key, ensuring that writes and storage are uniformly distributed across logical partitions to prevent hot partitioning. In the event of a regional outage, Cosmos DB automatically routes traffic to other configured write regions, maintaining continuous availability.

Step-by-Step Solution

1
Analyze write performance and replication requirements.
Identify that a multi-region write configuration in Azure Cosmos DB is needed to support write-heavy telemetry updates across East US, West Europe, and Southeast Asia with sub-10ms latency.
Multi-region write capability allows write operations to be processed locally in each region, minimizing WAN latency.
2
Determine the partition key strategy to prevent hot partitioning.
Select the unique scooter identifier (high cardinality) instead of status (low cardinality).
High-cardinality keys distribute the write volume and storage evenly across physical partitions, preventing hot spots and rate-limiting.
3
Evaluate disaster recovery requirements.
Ensure regional failover mechanisms are in place via multi-region replication rather than relying on a single region or backups.
Cosmos DB automatically replicates data across all configured regions, allowing for zero-data-loss failover in the event of a regional disaster.

Key Concept

Partition key design, global replication, and high availability in Azure Cosmos DB.
Estimated Time:1m 30s
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Topics

Azure Cosmos DB and NoSQL Solutions

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