Is there data loss when a Vertica node in a three node cluster goes down?
DX NetOps Performance Management
If a single node in a three node cluster goes down then the load is shared between the nodes that are up, including the workload for the failed node. Therefore there is a slight performance degradation but no data loss. Note the K-Safety must be 1 or higher for Vertica to accomplish fault tolerance and avoid data loss. If the K-Safety=0 then data loss is expected (Vertica will shutdown). The values are 0, 1 (3 nodes) or 2 (5 nodes).
To determine the K-safety state of a running database, execute the following SQL command on Vertica node:
=> SELECT current_fault_tolerance FROM system;
current_fault_tolerance ---------------- 1
If Vertica was setup from start as a three node Vertica cluster then the K-Safety should be 1. However if Vertica was installed as a single Vertica nodes and later decide to included two additional nodes to form a three node cluster then the K-Safety is likely to be 0. If this applies to you then please open a support case with Broadcom support.