Autocommit action=MODIFY on file=Plan.md detected

Plan.md

@@ -2,9 +2,10 @@
    - flap when rolling out agent / deploying new agent version
        - even crash on big regions
    - network flap / rabbit partition
-       - pause-minority 
+       - pause-minority helped crash the cluster
    - reset cluster was ... the solution 
 
+
 - What's going on with rabbit ?
     - reproduce workload with rabbit perftest
     - oslo.metrics 
@@ -14,23 +15,32 @@
     - What we learned ?
         - rabbitmq does not like at all large queue/connection churn
         - identified issues were mostly related to neutron
+            - rabbit ddos
+                - too many queue declare
+                - too many tcp connection churn
+        - Nova rpc usage is clearly != neutron
 
         
-- under the hood ? RPC implementation in Openstack: aka oslo.messaging
+- 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
+            - call - reply (topic / transient for reply)
+            - cast (topic queue)
+            - cast / fanout=true  (fanout queue)
     - notifications: kafka
 
 
 - Journey to get stable
     - Infra 
         - split rabbit-neutron / rabbit-*
-        - scale some clusters to 5 node
+        - scale problematic clusters to 5 node
         - Upgrade to 3.10+
-    - openstack
-        - 
+            - quorum queue recommended
+    - oslo messaging improvment
+        - queue fixed naming to avoid 
+        - move from HA queue > Quorum queues
+        - replace 'fanout' queues by stream queues => reduce queue nb
+        - reduce queue declared by RPC server
+        - use same connection for mutiple topics
+