Add RabbitMQNotEqualQueueCritical alert

Change-Id: Ie2f15a2c2b391c4256626314565b69800ce5fc78
Related-bug: PROD-30594
(cherry picked from commit 2646ee2fe5660860db4791cd8878da50ff229fa4)
diff --git a/rabbitmq/meta/prometheus.yml b/rabbitmq/meta/prometheus.yml
index f005409..27a3cde 100644
--- a/rabbitmq/meta/prometheus.yml
+++ b/rabbitmq/meta/prometheus.yml
@@ -27,6 +27,16 @@
       annotations:
         summary: "RabbitMQ service outage"
         description: "All RabbitMQ services are down."
+    RabbitMQUnequalQueueCritical:
+      if: >-
+        max(rabbitmq_overview_queues) != min(rabbitmq_overview_queues)
+      for: 10m
+      labels:
+        severity: critical
+        service: rabbitmq
+      annotations:
+        summary: "RabbitMQ service has unequal number of queues"
+        description: "RabbitMQ service has unequal number of queues across cluster instances."
     RabbitmqDiskFullWarning:
 {%- endraw %}
       if: >-