Multi-node support - This feature adds new cluster nodes to a cluster. So far the changes in metric data are only shown on a single node. Orphaned host or network nodes (due to a node failure or resource constraints) will be removed by SMA to create a healthy cluster. The first supported supported configuration is two nodes with one of the nodes as the master and the second one as the slave. If the master node fails, the slave will become the new master but the slave will not have access to any data - its metric data will be lost. The next supported configurations are three nodes as the master with one as the client and two slaves. A failed master node will automatically be removed from the cluster, leaving the remaining two nodes unchanged. The client represents some other node other than CircleCI or the host on which the node runs. The client can be seen as a master for some metric data. Metric data from the client is only reported to the host that the client represents. These results are visible in the CircleCI Admin dashboard. For more info about the distinction between client nodes and host nodes check out the below documentation
Masterless high availability - This feature creates a stand-alone configuration with no master node. The configuration configures an initial set of client nodes and any new nodes added to the cluster to be automatically added as a slave. This configuration requires a minimum of 2 slave only. The initial config of clients will be the remaining clients of the configuration if any of them fail.
Limit client nodes - This feature allows limiting the number of client nodes in a configuration. This allows management of configurations without having to delete existing configuration if it contains too many client nodes.