Public preview: Add an Azure Cosmos DB custom endpoint in IoT Hub

Azure IoT Hub now supports the ability to set up an **Azure Cosmos DB account as a custom routing endpoint**. This will help route device data from IoT Hub to Azure Cosmos DB directly. The feature also allows the configuration of [Synthetic Partition Keys](https://learn.microsoft.com/en-us/azure/cosmos-db/nosql/synthetic-partition-keys) for writing data into Azure Cosmos DB which helps in optimised querying when working with large-scale data. Many IoT solutions require extensive downstream data analysis and pushing data into hyperscale databases. For example, IoT implementations in manufacturing and intelligent transport systems require hyperscale databases with extremely high throughput to process the continuous stream of data. Traditional SQL based relational databases cannot scale optimally and also become expensive once data scale increases. Azure Cosmos DB is best suited for such cases where the data needs to be analysed while it is being written. Until today, there was no direct way to get IoT device data into Azure Cosmos DB. You had to either set up a custom application or use other tools, such as Azure Functions or Azure Stream Analytics, to collect the streaming data and then write to Cosmos DB. This not only required additional development, but also increased the cost of the solution. You don’t need to do this any longer – with the new release, you can: * Configure an Azure Cosmos DB account as a custom endpoint within the IoT Hub * Use Synthetic Partition Keys to auto-generate partition keys based on your business logic * Create routing rules to send data directly to the defined Azure Cosmos DB endpoint Learn more about [custom endpoints ](https://learn.microsoft.com/en-us/azure/iot-hub/iot-hub-devguide-messages-d2c) * Azure IoT Hub * Azure Cosmos DB * Features * [ Azure Cosmos DB](https://azure.microsoft.com/en-gb/products/cosmos-db/) * [ Azure IoT Hub](https://azure.microsoft.com/en-gb/products/iot-hub/)