Durable Subscribers

When a durable subscriber is disconnected from the EMS server, the server continues to accumulate messages for the client. However, while the client is disconnected, there is no user associated with the durable subscriber. Because of this, the server cannot immediately check permissions for a message that is received when the client is not connected.

When a user later reconnects to the server and resubscribes to the durable subscription, the server checks permissions for the subscribe operation itself, but all messages in the backlog are delivered to the consumer without additional permission checks.