This article provides architectural insight into how ZooKeeper behaviour can influence High Availability (HA) stability in Juniper SSR deployments, particularly in scenarios involving frequent leader elections.

Frequent ZooKeeper leader elections were observed.

ZooKeeper process impacts the leader election and HA synchronisation mechanisms. In such a case, both nodes may simultaneously believe they are in the Active state for the Routing Manager role.

This leads to a situation where routing updates and control packets originating from the Routing Manager on one node are sent to another node that also considers itself Active, causing state inconsistency and network instability. Consequently, the system enters a split-brain condition, resulting in unpredictable or incorrect routing behaviour.