> took a node down to see how it behaves. All of a sudden I couldn't write or [snip] > me.prettyprint.hector.api.exceptions.HUnavailableException: : May not be [snip] > Default replication factor = 1
So you have an RF=1 cluster (only one copy of data) and you bring a node down. This fundamentally and necessarily means that the data on the node you brought down will be unavailable. If you want to survive node failures, use an RF above 1. And then make sure to use an appropriate consistency level. -- / Peter Schuller (@scode, http://worldmodscode.wordpress.com)