If I use ignite.cluster().forAttribute("key", "value) for select several nodes from cluster, can I include/exclude node to/from ClusterGroup runtime by changing attribute value?
This is not possible - node attributes are static and assigned on the startup. If you want to exclude a node from the group, you create a new group based on the original one. For example, you can do it like this:
// 'group' is the original cluster group.