In Apstra 5.1, off-box agents and analytics services are delivered as containerized workloads that consume CPU and memory within the Apstra cluster. When these workloads are concentrated on the controller node, the controller can become resource-constrained, impacting overall responsiveness and scaling limits. The supported architectural solution is to add a worker node (worker VM) and allow Apstra to place offbox (and, if applicable, iba) containers on that worker. This increases cluster capacity and shifts runtime load away from the controller, which should remain focused on core control-plane and management functions.

Juniper’s sizing guidance also treats worker nodes as the scalable unit for off-box agent growth: each VM node (controller or worker) supports a bounded number of off-box agents, and when one VM is insufficient, the prescribed approach is to increase capacity by adding worker nodes to the Apstra VM cluster. This method scales horizontally and avoids overloading the controller with operational containers.

While increasing CPU/memory on the controller might help temporarily, the documented design pattern for sustained growth is to distribute the off-box workloads across worker nodes. Switching to on-box agents is a different operational model and not the direct remediation for controller resource pressure in an off-box deployment.

Verified Juniper sources (URLs):

https://www.juniper.net/documentation/us/en/software/apstra5.1/apstra-install-upgrade/topics/ref/apstra-server-resources.html

https://www.juniper.net/documentation/us/en/software/apstra5.0/apstra-user-guide/topics/topic-map/apstra-cluster-nodes.html

https://www.juniper.net/documentation/us/en/software/apstra4.2/apstra-user-guide/topics/topic-map/apstra-cluster-nodes.html