keepUp

Keeps up the subscription, preventing it from closing from the server.

This operation is performed because a subscription lifetime is finite. Server cancels all subscriptions at some point, because maintaining them requires resources and the client cannot be trusted to cancel every subscription it creates.

Also, in some environments, HTTP requests to the server are required in order for a server instance to stay alive. If the environment kills off all server instances, there would be no one to propagate subscription updates to the clients.

Parameters

See also