KSafety in Vertica

K-Safety is the maximum number of Nodes , the cluster can afford to loose.

So k-Safety =1 => Cluster will continue to work , if 1 node fails. 

                              In other words, cluster will fail , if 2 nodes fail

To check system k-safety:

  

vsql=> select DESIGNED_FAULT_TOLERANCE, CURRENT_FAULT_TOLERANCE from system;

Where:

 DESIGNED_FAULT_TOLERANCE = The designed or intended K-Safety level.

 CURRENT_FAULT_TOLERANCE = The number of node failures the cluster can tolerate before it shuts down automatically.

To change k-safety value:

VSQL=> SELECT MARK_DESIGN_KSAFE ( k )

Where k

2 enables high availability if the schema design meets requirements for K-Safety=2

1 enables high availability if the schema design meets requirements for K-Safety=1

0 disables high availability