The replication.mode strict-sync-all option allow to create or convert all cluster members as synchronous replicas and enables at the same time the Patroni synchronous_mode_strict. This is a combination of the strict-all and sync-all replication modes and the cluster works with the highest HA possible in Postgres.
Setting this replication mode is quite simple. Here is an example.
cat << EOF | kubectl apply -f - apiVersion: stackgres.io/v1 kind: SGCluster metadata: namespace: failover name: sync-cluster spec: postgres: version: '16.1' instances: 6 sgInstanceProfile: 'size-s' pods: persistentVolume: size: '10Gi' configurations: sgPostgresConfig: 'pgconfig1' sgPoolingConfig: 'poolconfig1' prometheusAutobind: true nonProductionOptions: disableClusterPodAntiAffinity: true replication: mode: strict-sync-all role: ha-read syncInstances: 1 EOF $ kubectl -n failover exec -it sync-cluster-0 -c patroni -- patronictl list + Cluster: sync-cluster (7373750354182599290) -----+-----------+----+-----------+ | Member | Host | Role | State | TL | Lag in MB | +----------------+------------------+--------------+-----------+----+-----------+ | sync-cluster-0 | 10.244.0.11:7433 | Leader | running | 2 | | | sync-cluster-1 | 10.244.0.10:7433 | Sync Standby | streaming | 2 | 0 | | sync-cluster-2 | 10.244.0.4:7433 | Sync Standby | streaming | 2 | 0 | | sync-cluster-3 | 10.244.0.8:7433 | Sync Standby | streaming | 2 | 0 | | sync-cluster-4 | 10.244.0.13:7433 | Sync Standby | streaming | 2 | 0 | | sync-cluster-5 | 10.244.0.14:7433 | Sync Standby | streaming | 2 | 0 | +----------------+------------------+--------------+-----------+----+-----------+