max_bytes should be determined as a function of the available memory, a max value that cannot be exceeded and the number of nodes in the cluster.

If we have more cluster nodes, and everyone sends messages, then not changing max_value would lead to too many STABLE messages being sent !

An example could be: max_bytes="1m" cap="0.25" // 25% of the available heap

If we have 5 nodes in the cluster, max_bytes would be set to 5m. With a heap of 100MiB, if we have 30 nodes, max_bytes would be set to max(30Mib, 0.25 * 100 Mib) == 25 MiB.