Cluster replica configuration issue causing cluster unavailability

[yinbo]

Hi guys, I encountered an issue where I understand that the configuration is incorrect, but it shouldn't cause the FoundationDB cluster to become abnormal.

FoundationDB Version: 7.1.23

Issue description:

1. Set up a FoundationDB cluster with two nodes. Data can be read and written at this point; for example, set k v.
2. Modify the replicas using the command "configure double." This command times out and fails.
3. Try to get k. Currently, k cannot be read(), but the cluster status is ok.

fdb> writemode on
fdb> set k v
Committed (186295280)
fdb> get k
`k' is `v'
fdb> configure double
WARNING: Long delay (Ctrl-C to interrupt)
The database is available.
ERROR: The database is unavailable
Type `configure FORCE <TOKEN...>' to configure without this check
fdb> status

Using cluster file `/var/fdb/fdb.cluster'.

Configuration:
  Redundancy mode        - double
  Storage engine         - memory-2
  Coordinators           - 1
  Usable Regions         - 1

Cluster:
  FoundationDB processes - 2
  Zones                  - 2
  Machines               - 2
  Memory availability    - 8.0 GB per process on machine with least available
  Fault Tolerance        - 0 machines
  Server time            - 09/12/23 10:01:19

Data:
  Replication health     - Healthy
  Moving data            - 0.000 GB
  Sum of key-value sizes - 0 MB
  Disk space used        - 210 MB

Operating space:
  Storage server         - 1.0 GB free on most full server
  Log server             - 493.7 GB free on most full server

Workload:
  Read rate              - 15 Hz
  Write rate             - 0 Hz
  Transactions started   - 6 Hz
  Transactions committed - 0 Hz
  Conflict rate          - 0 Hz

Backup and DR:
  Running backups        - 0
  Running DRs            - 0

Client time: 09/12/23 10:01:19