4.1. Enabling Management Node High AvailabilityΒΆ
Management node HA and compute cluster are tightly coupled, so changing nodes in one usually affects the other. Take note of the following:
Each node in the HA configuration must meet the requirements to the management node listed in the Installation Guide. If the compute cluster is to be created, its hardware requirements must be added as well.
The HA configuration must include at least three nodes at all times. Because of this, removing nodes from the HA configuration (whether or not the compute cluster exists) is only possible if the required minimum remains after removal. For example, to remove one of the minimum three nodes from the HA configuration, a fourth node must be added to it first.
If the HA configuration has been created before the compute cluster, all nodes in it will be added to the compute cluster.
If the compute cluster has been created before HA configuration, only nodes in the compute cluster can be added to the HA configuration. For this reason, to add a node to HA configuration, add it to the compute cluster first.
If both the HA configuration and compute cluster include the same four or more nodes, a node must first be removed from the HA configuration to be removed from the compute cluster.
If both the HA configuration and compute cluster include the same three nodes (the required minimum), single nodes cannot be removed from the compute cluster. In such a case, the compute cluster can be destroyed completely, but the HA configuration will remain; this is also true vice versa, the HA configuration can be deleted, but the compute cluster will continue working.
To enable high availability for the management node and admin panel, do the following:
Make sure that each node is connected to a network with the Admin panel traffic type.
On the SETTINGS > Management node screen, open the MANAGEMENT NODE HA CONFIGURATION tab.
Select three to five nodes and click Create HA configuration.
On Configure network, check that correct network interfaces are selected on each node. Otherwise click the cogwheel icon for a node and assign networks with the Internal management and Admin panel traffic type to its network interfaces. Click PROCEED.
Next, on Configure network, provide one or more unique static IP addresses for the highly available admin panel, compute API endpoint, and interservice messaging. Click DONE.
Once the high availability of the management node is enabled, you can log in to the admin panel only at the specified static IP address (on the same port 8888).
To remove nodes from the HA setup, select them in the list on the MANAGEMENT NODE HA tab and click Release nodes.