Home > APEX > Cloud Platforms > Guides > Dell APEX Cloud Platform for Microsoft Azure Tech Book > Cluster Expansion
At initial release, the Dell APEX Cloud Platform for Microsoft Azure supports only expanding a cluster running a minimum of two nodes, and it must be configured to use the scalable network topology. With this case, you can add one node at a time to a maximum cluster size of 16 nodes.
There are plans to improve this stance in upcoming platform releases.
As seen with lifecycle management, cluster expansion is a wizard driven, heavily automated operation.
When the nodes for the expansion have been physically installed and properly connected to their network switch ports, we can launch the expansion process. This will launch a node discovery mode that uses IPv6 Multicast Listener Discovery (MLD) snooping to find available servers.
When discovery has been completed, four compatibility checks are run against the new hardware:
Figure 40. Compatibility checks are run by the platform to validate the addition of new nodes
Had any of these failed, we have been provided the details to correct the failures found.
The workflow also runs additional validation checks designed to ensure consistency and standardization are maintained across the platform after the cluster expansion takes place, and that resiliency has not been compromised.
Figure 41. Platform validation checks has been successfully completed
The process to add a node can take up to 2 hours, and the node is added with hostname, networking, and local administrator credentials configured. The process also rebalances the storage pool through a low priority operation not to impact the running workloads. Additional validations are run at this point to ensure normal cluster operation.
In case any failure happens during these configuration steps, the workflow would stop. For this circumstance a retry mechanism is included to rapidly resume the process from the failed step.