I cannot find the details about Rondb in its documents. If I don’t remember wrong, I’ve read in the “MySQL Cluster 7.5 inside and out” book, NDB data node cluster can scale up to 48 nodes, but the message address size is 16 bit. Can you guys give me some more details about this?
In MySQL Cluster 8.0 the number of data nodes was increased to 144. The total number of
data nodes, API nodes and MGM nodes is 255.
The message address is similar to IPv4 with 32 bits. Those 32 bits are using 16 bits for node id,
10 bits for thread id and 6 bits for module id. In API nodes we use 16 bits for node id and 16 bits
for thread.
Thus the protocol scales to 65535 nodes although we only support 255 for the moment.
The protocol scales to a few thousand threads and thus to a few thousands of CPUs per
data node (this was implemented in MySQL Cluster 8.0.23 which RonDB 21.04.0 is based on).
No changes in this area for RonDB compared to NDB so far.