Overview
The Celona Edge acts as the heart of a Celona private mobile network, providing both 4G LTE and 5G mobile services across the entire array of devices and applications connected via private cellular. It interconnects the Celona access points (AP) across the private local, and wide area networks, for control and user data plane processing.
The Celona Edge is based on Kubernetes microservices, with horizontal scalability and high availability enabled by design.
Celona Edge supports the clustering of multiple Edge Nodes to form a highly available and redundant Edge Cluster.
High Availability for Celona Edge Nodes comprises of;
Multi-node, failover capable Kubernetes cluster.
Virtual Router Redundancy Protocol (VRRP) in front of the Edge Cluster, providing load balancing.
How is this typically deployed?
Our minimum recommended deployment is a three-node Edge Cluster.
The diagram above shows 1 active leader & 2 standby leaders.
Virtual Router Redundancy Protocol (VRRP) is used to present a single consistent IP address for connection of Celona APs, thus minimizing downtime in the event of an Edge Node failure.
Each of the Edge Nodes is running both a Kubernetes Leader and Worker. Only one node can be Leader, any others will automatically enter Standby Leader mode.
All three Edge Nodes in the Cluster are Active Worker nodes, concurrently performing;
Application categorization
Traffic prioritization
Traffic forwarding
Endpoint connectivity
When devices connect to the Celona network, their connectivity and traffic are actively load-balanced across all three Edge Nodes in the Cluster.
What happens in the event of an Edge Node - Active Leader, failure?
If the Active Leader fails the Standby leader nodes will elect a new leader and this becomes the main recipient of VRRP forwarded traffic.
From the perspective of the Celona AP, the leader is always present at the same VRRP IP address.
In the event of an active leader failure in a 3-node edge cluster, there is a brief disruption in UE and AP connections. The standby leader takes over, with the entire UE reconnection process typically completed within 30-120 seconds, averaging around 60 seconds. APs, which establish control connections with the leader, typically reconnect in 4-5 seconds, ensuring minimal disruption during the failover process.
What happens in the event of a Worker failure?
Workers are always active on every Edge Node within the cluster. In the event of a Worker failure;
New connections and traffic will be routed to one of the remaining active workers.
Devices connected to the failed worker will failover to active workers in the cluster.
Once the failed worker is repaired it will rejoin the edge cluster as a follower and resume handling device connectivity.
This article provides details on how to create a High Availability Cluster using Celona Orchestrator.
Note: Please ensure that Celona Edge is on version 2308 or higher to access HA (High Availability) support for 5G.
Note: For High Availability, a minimum of 3-node edge cluster configuration is required, the 3-node edge cluster is supported by both Celona Edge Express and Edge Enterprise. In a 3-node edge cluster, a single node failure is supported and if the second node fails, network operations will be impacted and manual intervention is needed for recovery.