Vitess is a distributed MySQL orchestrator and clustering system designed for horizontal database scaling. It functions as sharding middleware that distributes data and load across multiple MySQL instances to handle growth beyond the capacity of a single machine.
The system provides a proxy layer that abstracts data distribution, allowing applications to query a cluster as a single logical database without knowing the physical location of the data. This is achieved through a routing mechanism that intercepts queries and directs them to the appropriate shards based on keyspace mappings.
The platform manages large-scale data distribution through the ability to split or merge database shards. It coordinates these resharding processes and atomic cutovers to rebalance load across the cluster with minimal downtime.