Important/urgent to-device messages (eg room keys) can get blocked behind big queues of less important ones

[richvdh]

Eg, if you have another client which spams out room key requests, those requests can take quite a long time to be delivered to a client, and during that time no m.room.encrypted events holding actual useful content are delivered.

[richvdh]

matrix-org/matrix-spec-proposals#3944 is one proposal to partially mitigate this

[pmaier1]

Outcome of crypto workshop today: We consider this input for future sync concepts, rather than trying to tackle this issue in the context of the current architecture. Main reason being that UTDs caused by this issue will resolve after some time and aren't permanent therefore.

[BillCarsonFr]

Here is a rageshake of a session experiencing late keys https://github.com/element-hq/element-x-android-rageshakes/issues/1377

As we can see, the queue is mostly room key requests.

"m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type: "m.room_key_request", .. }, RawEvent { event_type:

Given that key requests are disabled by default now should greatly improve the late key problem