Spec Lite: Glance cluster awareness

project: glance
problem: Individual glance nodes are fully un-aware that there might be other nodes operating in the same space. This lack of communication between the nodes causes issues separating workers and operating in different locations.
solution: We have message queues already utilized in notifications and other projects. Lets expand that for communications between different glance-api nodes to gain better operational efficiency.
impacts: DocImpact

alternatives: We could use something else than the message queues but effectively that would end up recreating something like registry but just as a message broker.
timeline: Possible initial functionality in Rocky, more use cases covered S and beyond. This can be expanded fairly easily so we can proceed as time permits.
assignee: jokke