1. What is Azure Cosmos DB Capacity Planning?

Azure Cosmos DB capacity planning involves calculating the required Request Units (RU) capacity to handle your application's throughput needs. RUs represent the computational resources required to perform database operations.

2. How Does the Calculator Work?

The calculator uses the RU capacity formula:

Where:

• \( Total\ Throughput \) — Total operations per second your application requires
• \( Per\ Item\ Cost \) — Request Units required per database operation

Explanation: This calculation helps determine the minimum RU/s capacity needed to support your application's throughput requirements based on the cost of individual operations.

3. Importance of RU Capacity Calculation

Details: Proper RU capacity planning is essential for optimizing costs while ensuring your application meets performance requirements. Under-provisioning can lead to throttling, while over-provisioning increases costs unnecessarily.

4. Using the Calculator

Tips: Enter your estimated total throughput in operations per second and the average RU cost per operation. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What factors affect per item cost in Cosmos DB?
A: Item size, indexing policy, consistency level, and operation type (read vs write) all impact the RU cost of operations.

Q2: How can I reduce my RU requirements?
A: Optimize queries, use efficient indexing, consider smaller item sizes, and choose appropriate consistency levels.

Q3: Can I change RU capacity after deployment?
A: Yes, Azure Cosmos DB allows you to scale RU capacity up or down based on your changing requirements.

Q4: What's the difference between manual and autoscale provisioning?
A: Manual provisioning sets a fixed RU/s limit, while autoscale automatically scales between a range based on actual usage.

Q5: How does partitioning affect RU capacity?
A: Proper partitioning distributes load evenly across partitions, preventing hot partitions and maximizing throughput efficiency.