Summary

  • A 1 November individual Internet-Draft puts a Configuration Agent in charge of the relay map and health reports used by a Media over QUIC load balancer. Each balancer must report which version it uses and how old it is.
  • Once that version passes the operator's maximum age, the balancer must reject new requests that depend on old health reports. Returning to an earlier map requires a new, higher version and an authenticated operator action.
  • Proxy mode can move a subscription to another relay. In redirect mode, a client that detects relay failure must return to the balancer for a new choice.

An old map at a busy entrance

A publisher is sending a live event. Subscribers are watching it. A new viewer presses play. An ordinary QUIC load balancer sees a connection; it does not know which video requests share a Track Namespace. The new MoQ-LB draft, announced to the MoQ list on 2 November, reads that namespace. It uses a shared Routing Table to put related requests on the same relay. The draft assumes the relays can also serve one another's requests. Good placement cuts the work and delay between them.

Who gets to decide where the next viewer goes? The Configuration Agent sets the table, the relay pool and the health reports. It sends each balancer a complete, authenticated snapshot. The balancer checks it, switches to a newer version in one step, and keeps the last good copy. It reports the active version and its age.

The operator sets a maximum age. After that deadline, a balancer MUST NOT place a new request if the choice depends on stale relay health. It rejects the request. A saved map can still exist while its authority to make that choice has expired. The viewer sees the refusal at the entrance. Sending the viewer to a relay whose health is unknown could instead reveal the problem during playback. The draft gives no universal number of minutes; a real service's configured limit and update delivery time would settle that risk.

A rollback has its own rule. The balancer cannot apply a snapshot whose version is no higher than the active one. To restore the old map, the operator publishes its contents with a new, higher version and authenticates the action. Copying yesterday's file back is not enough.

Proxy mode can create a short disagreement. One balancer may receive a relay's GOAWAY or lose its backend connection before its peers learn of the change. It should report that local finding to the Agent. Redirect mode has no backend connection to watch; it relies on the Agent's health report. This is a Standards-Track-intended individual Internet-Draft, with no reported rollout or outage.