I want to use Datastore (Firestore in Datastore mode) in europe-west1. Since Datastore is not available as a regional location in europe-west1 I will go with the multi-region location (which consists of europe-west1 and europe-west4 according to this doc).
Do I understand data replication correctly in that if I store data in Datastore, Google automatically stores all the data in both regions europe-west1, europe-west4?
Can I disable data replication in europe-west4 since I just want to use Datastore in europe-west1?
Also just for my understanding: If multi-regional means there is a Data Center in each region why are both not available as single regional location?
Any help is appreciated.
The multi-region in GCP makes all the data replication automatically and this is by design, so that you have higher availability, performance, and resource efficiency and this is out of your control, so you can't disable data replication in a multi-region environment.
To your second question there is nothing that justifies this in the documentation, so I assume unofficially that this happens because Google simply does not allow for individual regions for that particular reason because it's not the focus of that particular region and acts just as a replicated location for that particular product when set to multi-region.