Question

An e-commerce platform stores each customer's order in an 'orders' container partitioned by /customerId. The team needs an Azure Function triggered by the Cosmos DB change feed that, for every new or updated order, must (1) write a denormalized summary document to a 'customerOrderHistory' container and (2) push a message to a Service Bus queue for downstream fulfillment. The function must process changes reliably and scale across partitions automatically. Which approach correctly implements this integration?

Accepted Answer

Use the Cosmos DB trigger with a lease container, and within the same function bind an output to the 'customerOrderHistory' container and a Service Bus output binding, so each change is fanned out to both destinations.

Answer

Use a Timer trigger that queries the orders container every minute for recently modified documents, then writes to both destinations, since the change feed cannot invoke multiple outputs.

Answer

Use the Cosmos DB trigger but disable the lease container to avoid duplicate processing, and write only to 'customerOrderHistory' because a single function cannot have more than one output binding.

Answer

Use an HTTP trigger invoked by a change-feed pull-model loop in a separate service, then use the SDK directly to write to both destinations because output bindings are not supported for Cosmos DB writes.