What is clustering?
A cluster combines multiple managed devices to provide high availability for all clients.
- Benefits include seamless roaming
- Client and AP load balancing
- Stateful failover
- Seamless cluster upgrades
Note: ArubaOS 8.X does NOT support the clustering of the mobility conductor. Clustering is only for mobility controllers, virtual mobility controllers in a mobility conductor deployment.
- Clients are anchored to a single controller (cluster member) regardless of roaming status or connected AP.
- The roaming experience should be seamless – their L2/L3 information and sessions remain on the same mobility controller.
Client stateful failover
- There is full redundancy within the cluster.
- In the event of a cluster member failure, connected clients are failed over to the redundant cluster member.
- There is zero disruption to wireless connectivity.
Client load balancing
- Clients are automatically load-balanced within the cluster.
- Clients are moved among cluster numbers in a stateful manner, which prevents disruption of services.
AP load balancing
- As of AOS 8.1, APs automatically load-balanced across cluster members.
Items to remember
- The mobility conductor provides centralized management, configuration, and control of the environment.
- The cluster feature requires a mobility conductor-based deployment.
- There is no license required to use the clustering feature.
- APs do NOT terminate on the mobility conductor, nor does the mobility conductor service wireless clients.
- The fact that the mobility conductor CANNOT be a cluster member does not reduce the effectiveness of the cluster solution.
- Standalone controllers CANNOT be clustered.
|Cluster 1 – 70xx – Same OS version max 4 MD cluster||Cluster 2 – 72xx Same OS version Max 12 MD cluster||Cluster 3 – VMC Same OS version Max 4 VMC cluster|
Additional cluster deployment considerations
- All cluster members must run the same ArubaOS version (8.0 and higher)
- A mix of 72xx and 70xx MDs in the same cluster is NOT recommended. If MDs are mixed, the maximum number of cluster members is reduced to four.
- When the cluster terminates RAPs, max cluster members are reduced to four.
- The cluster feature and the high availability and AP fast failover are mutually exclusive.
The 2019 clustering configuration post can be found here