Node membership

I’ve created a 3 node cluster and it is working well.
I have question about node membership though: if I stop a node (after it has joined a cluster) and start it again, I don’t have to use the --join flag but it still figures out it is part of a cluster.
Where is this information kept? And is it ok to omit the --join flag on subsequent restarts, after a node is joined to the cluster?


Once a node joins the cluster, it persists the list of other nodes to local disk (in the --store) directory.
When it starts up again, it will look at its on-disk state, realize that it is already initialized, and use the stored list to find node addresses.
This means that subsequent restarts of the node can be done without the --join flag.

That said, it is still safe to pass the --join flag on restart.
One important case: if a lot of node addresses changed after the node is shut down, it’s good to provide an updated --join flag.


Thanks a lot.