Replication Distribution Tree

If a cluster has less than 32 leaves then you will see the following output when you run, SHOW REPLICATION STATUS.  In this case, the reference database shows the replication across each leaf.


However, if you have a cluster with 32 or more leaves, then all leaves are not displayed when you run SHOW REPLICATION STATUS on the master aggregator.  This is because a distribution tree comes into play resulting in the display of only one entry per database.


The distribution tree always fans out one link down from the master aggregator, as shown below. Leaf N1 is the root of the distribution tree and N2, N3, N4 are the other leaves.


You can run SHOW REPLICATION STATUS on the leaf N1 to see the status of it replicating to all the other nodes.