How to use persistent streams like "broadcast"?

Hi everyone,

I have an application that has several grains identified by a key of type String (an alphanumeric).

Reading the Streams documentation, I realized that each stream is identified by a GUID+namespace, and that each grain can only subscribe to that stream if it also has the same key GUID+Namespace. I need a solution similar to broadcast, but reliable and persistent.

So the question is: is there a way to create a single stream (with a fixed GUID) where a group of grains, regardless of their key, can subscribe to that stream?

My scenario is: I have 2 types of grains - Account and Order. At a certain time of the day, I need to notify all Account type grains that a certain routine (an external routine) has been executed, so that they can update their state. How to achieve this with Orleans streams in a reliable way?

Start with the Orleans Streams documentation and the stream subscription behavior described in the issue. Determine whether grains with different keys can subscribe to one fixed-GUID stream and what reliable, persistent pattern fits the Account notification scenario; done means the supported approach and its constraints are documented.

Written by the indexing model from the issue text.