Hi, As I know there is no limit on the number of nodes. The largest cluster one of Ignite users is building that I know about will have 2000 nodes - may be that was what caused confusion.
Please note that the default affinity function (RendezvousAffinityFunction) manages 1024 partitions by default. That means, for example, having a cluster of more than 1024 nodes without backups might not be the most efficient use of resources, although it still provides additional fault tolerance. You can customise number of partitions in the configuration.
