Hi, I deployed a HA-cluster with two master and a mysql instance. I noticed that there has a huge throughout from mysql to one of masters as shown in the page below all the time. Is this normal or how can I debug it? Thanks.

its pretty chatty, yeah. The throughput will be proportional to the load on the apiserver.

For a HA setup you need 3 or 5 control plane nodes.

not with external sql you don’t

@creamy-pencil-82913 You mean this is normal,right? Meanwhile, another master has little throughout, no load-balance. @sparse-fireman-14239 In my opinion, the apiserver is stateless, several apiservers just for load-balance, not for election，right？Additionally，two masters are written in docs(Two or more server nodes) :)

Well...technically you're HA as long as the external database stays up. Is your MySQL instance running on >1 node?

Correct, apiservers are stateless but the controllers are leader-elected and talk to the local apiserver. So you will effectively always have one node that's active and others standby

@rough-farmer-49135 Yes, there is only one MySQL instance running on one node.

That means that if you want to test how things work with an HA Kubernetes cluster, you're good. However if you're trying to protect yourself from a single point of failure, you've just moved it back from the control plane to the MySQL instance.