> curl -s "http://admin:admin@localhost:8404/stats;csv" | grep -E 'pg_leader|pg_replica' | awk -F',' '{print $2, $18, $56}'
pg1 UP 1752
pg2 DOWN -1
pg3 DOWN -1
BACKEND UP 1752
pg1 DOWN -1
pg2 DOWN -1
pg3 DOWN -1
BACKEND DOWN -1

> patronictl -c /etc/patroni/config.yml list
+ Cluster: pgcluster (7637598528541987072) -------+----+-----------+
| Member       | Host         | Role    | State   | TL | Lag in MB |
+--------------+--------------+---------+---------+----+-----------+
| pg-knoten-01 | pg-knoten-01 | Leader  | running |  3 |           |
| pg-knoten-02 | pg-knoten-02 | Replica | stopped |    |   unknown |
| pg-knoten-03 | pg-knoten-03 | Replica | stopped |    |   unknown |
+--------------+--------------+---------+---------+----+-----------+


Wenn das so aussieht, dann kann von den Replicas nicht gelesen werden.
Um das Problem zu beheben, müssen die Replicas (beide) reinitialisiert werden.


> patronictl -c /etc/patroni/config.yml reinit pgcluster pg-knoten-02
+ Cluster: pgcluster (7637598528541987072) -------+----+-----------+
| Member       | Host         | Role    | State   | TL | Lag in MB |
+--------------+--------------+---------+---------+----+-----------+
| pg-knoten-01 | pg-knoten-01 | Leader  | running |  3 |           |
| pg-knoten-02 | pg-knoten-02 | Replica | stopped |    |   unknown |
| pg-knoten-03 | pg-knoten-03 | Replica | stopped |    |   unknown |
+--------------+--------------+---------+---------+----+-----------+
Are you sure you want to reinitialize members pg-knoten-02? [y/N]: y
Failed: reinitialize for member pg-knoten-02, status code=503, (bootstrap from leader 'pg-knoten-01' already in progress)
Do you want to cancel it and reinitialize anyway? [y/N]: y
Success: reinitialize for member pg-knoten-02

> patronictl -c /etc/patroni/config.yml reinit pgcluster pg-knoten-03
+ Cluster: pgcluster (7637598528541987072) -------+----+-----------+
| Member       | Host         | Role    | State   | TL | Lag in MB |
+--------------+--------------+---------+---------+----+-----------+
| pg-knoten-01 | pg-knoten-01 | Leader  | running |  3 |           |
| pg-knoten-02 | pg-knoten-02 | Replica | stopped |    |   unknown |
| pg-knoten-03 | pg-knoten-03 | Replica | stopped |    |   unknown |
+--------------+--------------+---------+---------+----+-----------+
Are you sure you want to reinitialize members pg-knoten-03? [y/N]: y
Failed: reinitialize for member pg-knoten-03, status code=503, (bootstrap from leader 'pg-knoten-01' already in progress)
Do you want to cancel it and reinitialize anyway? [y/N]:  


Jetzt arbeiten die Replicas ordentliche und man kann von ihnen auch ordentlich lesen:


> patronictl -c /etc/patroni/config.yml list
+ Cluster: pgcluster (7637598528541987072) ---------+----+-----------+
| Member       | Host         | Role    | State     | TL | Lag in MB |
+--------------+--------------+---------+-----------+----+-----------+
| pg-knoten-01 | pg-knoten-01 | Leader  | running   |  6 |           |
| pg-knoten-02 | pg-knoten-02 | Replica | streaming |  6 |         0 |
| pg-knoten-03 | pg-knoten-03 | Replica | streaming |  6 |         0 |
+--------------+--------------+---------+-----------+----+-----------+

> curl -s "http://admin:admin@localhost:8404/stats;csv" | grep -E 'pg_leader|pg_replica' | awk -F',' '{print $2, $18, $56}'
pg1 UP 6000
pg2 DOWN -1
pg3 DOWN -1
BACKEND UP 6000
pg1 DOWN -1
pg2 UP -1
pg3 UP -1
BACKEND UP -1