- Issues with rabbit ?
   - flap when rolling out agent / deploying new agent version
       - even crash on big regions
   - network flap / rabbit partition
       - pause-minority 
   - reset cluster was ... the solution 

- What's going on with rabbit ?
    - reproduce workload with rabbit perftest
    - oslo.metrics 
    - rabbitmq exporter / grafana dashboards
    - smokeping between nodes

    - What we learned ?
        - rabbitmq does not like at all large queue/connection churn
        - identified issues were mostly related to neutron
             
     
- under the hood ? RPC implementation in Openstack: aka oslo.messaging
    - pub/sub
        - RPC server: setup endpoints / queues / listeners
            - topic, fanout mechanism
        - publish: rpc provided methods
            - call
            - cast
            - cast / fanout=true
    - notifications: kafka


- Journey to get stable
    - Infra 
        - split rabbit-neutron / rabbit-*
        - scale some clusters to 5 node
        - Upgrade to 3.10+
    - openstack
        -