World’s Most Advanced Features and Un-Seen Benefits
True Multi-master, Active-Active Cluster Read and write to any node at any time.
Synchronous Replication No slave lag, no data is lost at node crash.
Tightly Coupled All nodes hold the same state. No diverged data between nodes allowed.
Multi-threaded Slave For better performance. For any workload.
No Master-Slave Failover Operations or Use of VIP.
Hot Standby No downtime during failover (since there is no failover).
Automatic Node Provisioning No need to manually back up the database and copy it to the new node.
Transparent to Applications Required no (or minimal changes) to the application.
No Read and Write Splitting Needed.
Easy to Use and Deploy
Cloud Implementations with
An additional benefit of Galera Cluster is good cloud support. Automatic node provisioning makes elastic scale-out and scale-in operations painless. Galera Cluster has been proven to perform extremely well in the cloud, such as when using multiple small node instances, across multiple data centers—AWS zones, for example—or even over Wider Area Networks.
Optimized Network Protocol.
Packets exchanged over WAN only at transaction commit time
Detection and automatic Eviction of Unreliable Nodes
Transaction is sent to each datacenter only once
Galera replication happens at transaction commit time, by broadcasting transaction write set to the cluster for applying.
Client connects directly to the DBMS and experiences close to native DBMS behavior.
wsrep API (write set replication API), defines the interface between Galera replication and the DBMS.
Synchronous vs. Asynchronous Replication
It’s always highly available (there is no data loss when one of the nodes crashes, and data replicas are always consistent)
Transactions can be executed on all nodes in parallel.
It can guarantee causality across the whole cluster (SELECT S issued after transaction T will always see the effects of transaction even if it is executed on another node)