MySQL replication in action - Part 4 - star and hybrid topologies

Previous episodes:

• MySQL replication monitoring 101
• MySQL replication in action - Part 1: GTID & Co
• MySQL replication in action - Part 2 - Fan-in topology
• MySQL replication in action - Part 3 - All-masters P2P topology

Introducing star topology.

In all-masters P2P topologies, we have seen that we have a way of deploying a topology where all nodes are masters, and achieve better efficiency and stability than ring topologies. That method comes at the price of a complex setup, which requires, for a N-node cluster, N*(N-1) connections.
We can achieve the same result as in a P2P all-masters topology by trading connections for stability. In a star topology (Figure 1) all nodes are masters, but they do not connect to each other directly. There is a special node, named hub, which receives the changes produced by each endpoint and spreads them to the others.

Figure 1 - A star topology

MySQL schema maintenance

At CodeBits I had my first session about MySQL schema maintenance. I covered the basic command line possibilities before coming to the recommended tool, MySQL Workbench. The slides are available at slideshare.

Interesting questions: ([updated] with answers from the development team

• [Q] Are there plans to administer MySQL Cluster with Workbench?
  [A] Not that we know of.


• [Q] Can Workbench deal with user permission maintenance across servers? (especially in cases where development and production users can't have the same privileges)
  [A] YES. It's in the roadmap


• [Q] Can MySQL Workbench help editing stored routines? Apparently, you can't change the routine code with ALTER PROCEDURE/FUNCTION, but you need to drop it, recreate it, and eventually change privileges.
  [A] Not that we know of, although something can be done with Proxy to ease this problem.


• [Q] Is the code for the plugin documented for contributors?
  [A] Not yet, but it's going to be soon.