How do I replace a leaf node that has a hardware issue?
Replace a Failed Leaf Node in a Redundancy-1 Cluster
In Redundancy-1, there are no extra online copies of your data; all partitions are master partitions. In the event of a leaf node failure, your data is offline until you reintroduce the leaf back into the system and restore the database(s) from backup if the data directories from the failed host are unrecoverable.
Replace a Failed Leaf Node in a Redundancy-2 Cluster
In Redundancy-2, SingleStore handles node failures by promoting the appropriate replica partitions into masters so that your databases remain online. In this case, as long as the pair leaves for the node(s) that went offline are still in an online healthy state, replacing a host in this scenario would be an online operation.
For a more in-depth guide to replacing a leaf node in a Redundancy-1 or 2 environments with the accompanying syntax, review the steps in the Documentation.