id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	launchpad_bug
2555	publish-and-subscribe to change events on mutables	zooko	daira	"Currently if a client wants to keep track of changes being made by someone else to a mutable, it has to poll that mutable. In Magic Folder, for example, we poll every few seconds. Polling is terrible! It has bad latency (a few seconds) and also bad load (new requests every few seconds).

Instead we should implement a publish-and-subscribe notification system by which clients can maintain an open (but idle) connection to a server, and then get low-latency, cheap notifications from servers about events.

The storage server should provide an API which does something like this:

{{{
remote_registerWatcher(watcher, storage_index, previous_watcher=None)
}}}
"	defect	new	normal	undecided	code-mutable	1.10.1		magic-folder