Guarantees¶

Quality of Service¶

In the following lists of guarantees, subsequent items include all guarantees given by preceding items.

Ordering¶

1. Unordered: Events are delivered in (potentially) arbitrary order.
2. Ordered: Every listener receives the events of one informer in the order the informer sent the events. No guarantees are given for events of multiple informers.

Independent of the requested ordering, no relation is guaranteed for events arriving at multiple listeners.

Reliability¶

1. Unreliable: Events may be dropped and not be visible to a listener.
2. Reliable: Messages are guaranteed to be delivered. Otherwise an error is raised.

Threading¶

• Informer is thread-safe
• Listener is thread-safe. This implies:
  • Adding/Removing filters from arbitrary threads does
  • Add/Remove handlers