checkout Streamy :
good if you need basic websocket message chat-style functionality, and you don’t want to store the messages in the database.
In the above use case for getting the status of an upload, I would just use Meteor’s pub / sub as it is. I would suggest to insert an Upload Document into the database when the upload starts, not after it succeeds. If the upload fails the server can set a property on the Mongo Document and the client will be notified via pub / sub ‘changed’ which will occur on the Document.