Support for multiple instances of a service for load balancing

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https://docs.dapr.io/developing-applications/building-blocks/service-invocation/service-invocation-overview/

Following this link I'm trying to run multiple instances of cart service. i.e when I start using the dapr I'm trying to start multiple instances using the same app id "cart" which results in the following exception.

**_dapr with ID cart is already running_**

Please let me know if my understanding is correct.