AWS Availability Zones and partitioning process classes


What is the correct way to make FoundationDB split process classes evenly among Availability Zones in AWS?

After reading the documentation I’ve tried the following:


  • 9 EC2 instances, 3 in each Availability Zone
  • 3 storage servers (1 per AZ), 6 transaction log processes (2 per AZ) - all set in the /etc/foundationdb/foundationdb.conf.
  • Replication mode single.
  • locality_zoneid = <AZ_ID> (e.g. eu-central-1a)

For some reason foundationdb picked 3 transaction logs only (probably is the default). I noticed that 2 were from same AZ.

My expectation was that the transaction logs would be picked 1 for each AZ (there are 3 in total in eu-central-1 region).

Was my expectation/configuration wrong perhaps?
The goal was that by default there is 1 transaction log per distinct locality_zoneid.