Answer
Junos Space uses the mod_proxy load balancer module within the Apache HTTP server. The load balancer module is configured to use the default load-balancing method (lbmethod=byrequests), which provides a weighted round-robin algorithm. However, because all nodes in the cluster have the same weight, this means that a round-robin strategy is used for load distribution. The load balancer is also configured to use sticky sessions (using the JSESSIONID cookie), which ensures that all HTTP requests that are part of the same login session are forwarded to the same node in the cluster.
For more information, click High Availability and Disaster Recovery Guide.