I ntroducon to MemSQL Data Replicaon A MemSQL cluster is resilient to failure with automac failover and self-healing capabilies. MemSQL allows you to store a redundant copy of data within a cluster. Leaf nodes are organized into availability groups such that each node is paired with a node in the other availability group. Each leaf node has a pair that replicates its data, and can be configured to do so synchronously or asynchronously. In case of node failure, MemSQL restores data and promotes replica parons to put the cluster back online. Figure 16. Replicas in MemSQL are promoted to master MemSQL also supports fully automac cross-data center replicaon that can be provisioned with a single command. The replica cluster stores a read-only copy of data asynchronously replicated from the primary cluster. In the event of a major failure in the primary cluster, MemSQL can promote the secondary cluster, immediately making it a "full" MemSQL cluster. In addion to providing disaster recovery assurance, the secondary cluster can also be used for heavy read-only workloads. 22