oslo.messaging/doc/source/user/FAQ.rst

Frequently Asked Questions

I don't need notifications on the message bus. How do I disable them?

Notification messages can be disabled using the noop notify driver. Set driver = noop in your configuration file under the [oslo_messaging_notifications] section.

Why does the notification publisher create queues, too? Shouldn't the subscriber do that?

The notification messages are meant to be used for integration with external services, including services that are not part of OpenStack. To ensure that the subscriber does not miss any messages if it starts after the publisher, oslo.messaging ensures that subscriber queues exist when notifications are sent.

How do I change the queue names where notifications are published?

Notifications are published to the configured exchange using a topic built from a base value specified in the configuration file and the notification "level". The default topic is notifications, so an info-level notification is published to the topic notifications.info. A subscriber queue of the same name is created automatically for each of these topics. To change the queue names, change the notification topic using the topics configuration option in [oslo_messaging_notifications]. The option accepts a list of values, so it is possible to publish to multiple topics.

What are the other choices of notification drivers available?

• messaging Send notifications using the 1.0 message format.
• messagingv2 Send notifications using the 2.0 message format (with a message envelope).
• routing Configurable routing notifier (by priority or event_type).
• log Publish notifications via Python logging infrastructure.
• test Store notifications in memory for test verification.
• noop Disable sending notifications entirely.