**Context:** We are using a MariaDB Gallera cluster with (only) 2 master nodes for a web application. Last night we had a power failure and now we can't seem to recover the data and found out the database was corrupt on both nodes. Our initial impression on this setup was if one node goes down, the other would quickly act as the primary node. 

My questions are, 

1. Is there a way to set a cluster up so there is always a backup node which will automatically be replicated if one of the nodes go down? Specially if there is a power failure.
2. What would be the correct implementation of the gallery cluster?