APPLIES TO: 
NoSQL
Priority based execution allows users to specify priority of requests sent to Azure Cosmos DB. In cases where the number of requests exceeds the capacity that can be processed within the configured Request Units per second (RU/s), then Azure Cosmos DB throttles low priority requests to prioritize the execution of high priority requests.
How many priority levels are supported by priority-based execution?
There are only two priority levels supported, Low and High.
What is the default priority of a request?
All requests are of High priority by default.
Can I change default priority level of requests in Azure Cosmos DB account?
Yes, you can change the default priority level of requests for an Azure Cosmos DB account using Azure CLI.
Does enabling priority based execution mean reserving a fraction of RU/s for high priority requests?
No, there's no reservation of RU/s. The users can use all their provisioned RU/s irrespective of the priority of requests.
What are the pricing changes associated with this feature?
There's no cost associated with this feature, it's free of charge.
Next steps
- Learn more about Priority-based execution