A multi-region location consists of a defined set of regions where multiple replicas of the database are stored. Each replica is either a read-write replica which contains all of the data in the database or a witness replica which does not maintain a full set of data but participates in replication.
By replicating the data between multiple regions, data can continue to be served even with the loss of an entire region. Within a region, data is replicated across zones so that data can continue to be served within that region even with the loss of a zone.
Each multi-region location includes at least two read-write regions that serve
read and write traffic. A third region is a witness region in nam5 and
a read-write region in eur3.
The following multi-region locations are available:
| Multi-Region Name | Multi-Region Description | Read-Write Regions | Witness Region |
|---|---|---|---|
eur3 |
Europe | europe-west1 (Belgium), europe-west4 (Netherlands), europe-north1 (Finland) |
|
nam5 |
United States | us-central1 (Iowa), us-central2 (Oklahoma—private GCP region) |
us-east1 (South Carolina) |