图片来源于：https://docs.percona.com/postgresql/12/solutions/high-availability.html#architecture-layout

1，patronictl 查看集群状态

patronictl -c /usr/local/pgsql16/patroni/patroni.yml list，修改参数后会显示Pending restart和Pending restart reason 列

#patroni集群状态查看root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml list+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+| Member   | Host                 | Role    | State     | TL | Lag in MB |+----------+----------------------+---------+-----------+----+-----------+| ubuntu08 | 192.168.152.115:9000 | Replica | streaming |  5 |         0 || ubuntu09 | 192.168.152.116:9000 | Replica | streaming |  5 |         0 || ubuntu10 | 192.168.152.117:9000 | Leader  | running   |  5 |           |+----------+----------------------+---------+-----------+----+-----------+#修改相关参数之后root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml list+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+-----------------+----------------------------+| Member   | Host                 | Role    | State     | TL | Lag in MB | Pending restart | Pending restart reason     |+----------+----------------------+---------+-----------+----+-----------+-----------------+----------------------------+| ubuntu08 | 192.168.152.115:9000 | Replica | streaming |  2 |         0 | *               | max_connections: 100->120  ||          |                      |         |           |    |           |                 | shared_buffers: 1GB->512MB |+----------+----------------------+---------+-----------+----+-----------+-----------------+----------------------------+| ubuntu09 | 192.168.152.116:9000 | Replica | streaming |  2 |         0 | *               | max_connections: 100->120  ||          |                      |         |           |    |           |                 | shared_buffers: 1GB->512MB |+----------+----------------------+---------+-----------+----+-----------+-----------------+----------------------------+| ubuntu10 | 192.168.152.117:9000 | Leader  | running   |  2 |           | *               | max_connections: 100->120  ||          |                      |         |           |    |           |                 | shared_buffers: 1GB->512MB |+----------+----------------------+---------+-----------+----+-----------+-----------------+----------------------------+

2，patronictl 暂停auto failover

某些情况下，比如重启服务器等运维措施实施的时候，此时并不想改变数据库的主从关系，就需要暂停auto failover，命令为patronictl pause暂停auto failover

-- 禁用 auto failover，如果没有启动 patroni，执行 patronictl pause 会失败patronictl -c /usr/local/pgsql16/patroni/patroni.yml pauseroot@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml pauseSuccess: cluster management is pausedroot@ubuntu08:/usr/local/pgsql16/patroni# patronictl listroot@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml show-configloop_wait: 10master_start_timeout: 300master_stop_timeout: 0max_timelines_history: 0maximum_lag_on_failover: 1048576#备注行：启用之后，用show-config看到pause: true配置项pause: truepostgresql:  parameters:    archive_command: test ! -f /usr/local/pgsql16/pg_wal_arch/%f && cp %p /usr/local/pgsql16/pg_wal_arch/%f    archive_mode: 'on'    archive_timeout: 1800s    hot_standby: 'on'    log_autovacuum_min_duration: 0    log_checkpoints: 'on'    log_connections: 'on'    log_destination: stderr    log_directory: log    log_disconnections: 'on'    log_file_mode: '0600'    log_filename: postgresql-%Y-%m-%d_%H%M%S.log    log_hostname: 'on'    log_line_prefix: '%m [%p] user:%u,db:%d,app:%a,host:%h '    log_lock_waits: 'on'    log_min_duration_statement: 1    log_recovery_conflict_waits: 'on'    log_replication_commands: 'on'    log_rotation_age: 1d    log_statement: ddl    log_temp_files: 1    log_timezone: Asia/Shanghai    logging_collector: 'on'    max_connections: 100    max_locks_per_transaction: 64    max_prepared_transactions: 0    max_replication_slots: 10    max_wal_senders: 10    max_worker_processes: 8    shared_buffers: 1024MB    track_commit_timestamp: 'off'    wal_keep_segments: 8    wal_level: hot_standby    wal_log_hints: 'on'    work_mem: 32MB  pg_hba:  - host replication repl_user 0.0.0.0/0 md5  - host all all 0.0.0.0/0 md5  use_pg_rewind: true  use_slots: trueretry_timeout: 10synchronous_mode: falsettl: 30# 启用 auto failover patronictl -c /usr/local/pgsql16/patroni/patroni.yml resume# 启用之后，用show-config看不到pause: trueroot@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml resumeSuccess: cluster management is resumedroot@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml show-configloop_wait: 10master_start_timeout: 300master_stop_timeout: 0max_timelines_history: 0maximum_lag_on_failover: 1048576postgresql:  parameters:    archive_command: test ! -f /usr/local/pgsql16/pg_wal_arch/%f && cp %p /usr/local/pgsql16/pg_wal_arch/%f    archive_mode: 'on'    archive_timeout: 1800s    hot_standby: 'on'    log_autovacuum_min_duration: 0    log_checkpoints: 'on'    log_connections: 'on'    log_destination: stderr    log_directory: log    log_disconnections: 'on'    log_file_mode: '0600'    log_filename: postgresql-%Y-%m-%d_%H%M%S.log    log_hostname: 'on'    log_line_prefix: '%m [%p] user:%u,db:%d,app:%a,host:%h '    log_lock_waits: 'on'    log_min_duration_statement: 1    log_recovery_conflict_waits: 'on'    log_replication_commands: 'on'    log_rotation_age: 1d    log_statement: ddl    log_temp_files: 1    log_timezone: Asia/Shanghai    logging_collector: 'on'    max_connections: 100    max_locks_per_transaction: 64    max_prepared_transactions: 0    max_replication_slots: 10    max_wal_senders: 10    max_worker_processes: 8    shared_buffers: 1024MB    track_commit_timestamp: 'off'    wal_keep_segments: 8    wal_level: hot_standby    wal_log_hints: 'on'    work_mem: 32MB  pg_hba:  - host replication repl_user 0.0.0.0/0 md5  - host all all 0.0.0.0/0 md5  use_pg_rewind: true  use_slots: trueretry_timeout: 10synchronous_mode: falsettl: 30

3，patronictl 重启集群

root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml list+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+-----------------+----------------------------+| Member   | Host                 | Role    | State     | TL | Lag in MB | Pending restart | Pending restart reason     |+----------+----------------------+---------+-----------+----+-----------+-----------------+----------------------------+| ubuntu08 | 192.168.152.115:9000 | Replica | streaming |  2 |         0 | *               | max_connections: 100->120  ||          |                      |         |           |    |           |                 | shared_buffers: 1GB->512MB |+----------+----------------------+---------+-----------+----+-----------+-----------------+----------------------------+| ubuntu09 | 192.168.152.116:9000 | Replica | streaming |  2 |         0 | *               | max_connections: 100->120  ||          |                      |         |           |    |           |                 | shared_buffers: 1GB->512MB |+----------+----------------------+---------+-----------+----+-----------+-----------------+----------------------------+| ubuntu10 | 192.168.152.117:9000 | Leader  | running   |  2 |           | *               | max_connections: 100->120  ||          |                      |         |           |    |           |                 | shared_buffers: 1GB->512MB |+----------+----------------------+---------+-----------+----+-----------+-----------------+----------------------------+root@ubuntu08:/usr/local/pgsql16/patroni#root@ubuntu08:/usr/local/pgsql16/patroni#root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml restart pg_cluster_wy_prod+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+-----------------+----------------------------+| Member   | Host                 | Role    | State     | TL | Lag in MB | Pending restart | Pending restart reason     |+----------+----------------------+---------+-----------+----+-----------+-----------------+----------------------------+| ubuntu08 | 192.168.152.115:9000 | Replica | streaming |  2 |         0 | *               | max_connections: 100->120  ||          |                      |         |           |    |           |                 | shared_buffers: 1GB->512MB |+----------+----------------------+---------+-----------+----+-----------+-----------------+----------------------------+| ubuntu09 | 192.168.152.116:9000 | Replica | streaming |  2 |         0 | *               | max_connections: 100->120  ||          |                      |         |           |    |           |                 | shared_buffers: 1GB->512MB |+----------+----------------------+---------+-----------+----+-----------+-----------------+----------------------------+| ubuntu10 | 192.168.152.117:9000 | Leader  | running   |  2 |           | *               | max_connections: 100->120  ||          |                      |         |           |    |           |                 | shared_buffers: 1GB->512MB |+----------+----------------------+---------+-----------+----+-----------+-----------------+----------------------------+When should the restart take place (e.g. 2025-09-26T08:49)  [now]:Are you sure you want to restart members ubuntu08, ubuntu09, ubuntu10? [y/N]: yRestart if the PostgreSQL version is less than provided (e.g. 9.5.2)  []:Success: restart on member ubuntu08Success: restart on member ubuntu09Success: restart on member ubuntu10root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml list+ Cluster: pg_cluster_wy_prod (7553485872297570126) --+----+-----------+| Member   | Host                 | Role    | State   | TL | Lag in MB |+----------+----------------------+---------+---------+----+-----------+| ubuntu08 | 192.168.152.115:9000 | Replica | running |  2 |         0 || ubuntu09 | 192.168.152.116:9000 | Replica | running |  2 |         0 || ubuntu10 | 192.168.152.117:9000 | Leader  | running |  2 |           |+----------+----------------------+---------+---------+----+-----------+root@ubuntu08:/usr/local/pgsql16/patroni#

4，patronictl 查看参数

patronictl -c /usr/local/pgsql16/patroni/patroni.yml  show-config查看PostgreSQL参数设置，需要注意的是，查看出来的参数是从ectd存储中读取出来的，而不是配置文件本身的内容，配置文件自身的内容会在启动的时候写入到etcd。

另一个细节是：如果通过edit-config增加相关参数，编辑完成后用show-config再次查看，相关的参数在编辑模式中显示的位置是会变化的，再次说明，edit-config编辑参数最终写入到了ectd中，显示的时候从ectd中读取出来，而不是patroni.yml文件本身，这一点非常容易误解。

root@ubuntu08:/usr/local/pgsql16/patroni#  patronictl -c /usr/local/pgsql16/patroni/patroni.yml  show-configloop_wait: 10master_start_timeout: 300master_stop_timeout: 0max_timelines_history: 0maximum_lag_on_failover: 1048576postgresql:  parameters:    archive_command: test ! -f /usr/local/pgsql16/pg_wal_arch/%f && cp %p /usr/local/pgsql16/pg_wal_arch/%f    archive_mode: 'on'    archive_timeout: 1800s    hot_standby: 'on'    log_autovacuum_min_duration: 0    log_checkpoints: 'on'    log_connections: 'on'    log_destination: stderr    log_directory: log    log_disconnections: 'on'    log_file_mode: '0600'    log_filename: postgresql-%Y-%m-%d_%H%M%S.log    log_hostname: 'on'    log_line_prefix: '%m [%p] user:%u,db:%d,app:%a,host:%h '    log_lock_waits: 'on'    log_min_duration_statement: 1    log_recovery_conflict_waits: 'on'    log_replication_commands: 'on'    log_rotation_age: 1d    log_statement: ddl    log_temp_files: 1    log_timezone: Asia/Shanghai    logging_collector: 'on'    max_connections: 100    max_locks_per_transaction: 64    max_prepared_transactions: 0    max_replication_slots: 10    max_wal_senders: 10    max_worker_processes: 8    shared_buffers: 1024MB    track_commit_timestamp: 'off'    wal_keep_segments: 8    wal_level: hot_standby    wal_log_hints: 'on'    work_mem: 32MB  pg_hba:  - host replication repl_user 0.0.0.0/0 md5  - host all all 0.0.0.0/0 md5  use_pg_rewind: true  use_slots: trueretry_timeout: 10synchronous_mode: falsettl: 30

5，修改参数

5.1  edit-config方式修改参数1

root@ubuntu08:/usr/local/pgsql16/patroni#  patronictl -c /usr/local/pgsql16/patroni/patroni.yml edit-config---+++@@ -28,13 +28,13 @@     log_temp_files: 1     log_timezone: Asia/Shanghai     logging_collector: 'on'-    max_connections: 100+    max_connections: 120     max_locks_per_transaction: 64     max_prepared_transactions: 0     max_replication_slots: 10     max_wal_senders: 10     max_worker_processes: 8-    shared_buffers: 1024MB+    shared_buffers: 512MB     track_commit_timestamp: 'off'     wal_keep_segments: 8     wal_level: hot_standbyApply these changes? [y/N]: yConfiguration changedroot@ubuntu08:/usr/local/pgsql16/patroni#

5.2 edit-config方式修改参数2

patronictl -c /usr/local/pgsql16/patroni/patroni.yml edit-config -s 'postgresql.parameters.max_connections=300'

root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml list+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+| Member   | Host                 | Role    | State     | TL | Lag in MB |+----------+----------------------+---------+-----------+----+-----------+| ubuntu08 | 192.168.152.115:9000 | Replica | streaming |  2 |         0 || ubuntu09 | 192.168.152.116:9000 | Replica | streaming |  2 |         0 || ubuntu10 | 192.168.152.117:9000 | Leader  | running   |  2 |           |+----------+----------------------+---------+-----------+----+-----------+root@ubuntu08:/usr/local/pgsql16/patroni#   patronictl -c /usr/local/pgsql16/patroni/patroni.yml edit-config -s 'postgresql.parameters.max_connections=300'---+++@@ -28,7 +28,7 @@     log_temp_files: 1     log_timezone: Asia/Shanghai     logging_collector: 'on'-    max_connections: 120+    max_connections: 300     max_locks_per_transaction: 64     max_prepared_transactions: 0     max_replication_slots: 10Apply these changes? [y/N]: yConfiguration changedroot@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml list #备注：patronictl list执行后，这里一开始不显示需要重启，过几秒中才能看到+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+-----------------+---------------------------+| Member   | Host                 | Role    | State     | TL | Lag in MB | Pending restart | Pending restart reason    |+----------+----------------------+---------+-----------+----+-----------+-----------------+---------------------------+| ubuntu08 | 192.168.152.115:9000 | Replica | streaming |  2 |         0 | *               | max_connections: 120->300 || ubuntu09 | 192.168.152.116:9000 | Replica | streaming |  2 |         0 | *               | max_connections: 120->300 || ubuntu10 | 192.168.152.117:9000 | Leader  | running   |  2 |           | *               | max_connections: 120->300 |+----------+----------------------+---------+-----------+----+-----------+-----------------+---------------------------+

关于修改参数的patronictl edit-config， 语法上是patronictl 指定一个配置文件修改，修改后实际上修改的etcd的中的记录，然后etcd中的new_value记录的会分发到etcd的所有节点，但是其old_value并不是修改前的值，而是默认值，我一直以为搞错了，试了三次才发现是这个规律 。

5.3 PostgreSQL 的 ALTER SYSTEM SET 命令

--修改work_memALTER SYSTEM SET work_mem TO '8MB';SELECT pg_reload_conf();

6，patroni切换PostgreSQL主从

6.1 patronictl switchover

patronictl switchover：手动故障转移测试，它仅在集群健康(有leader)时才起作用，并允许在指定时间安排切换。patronictl switchover允许在集群中的任意节点执行切换操作

root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml list+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+| Member   | Host                 | Role    | State     | TL | Lag in MB |+----------+----------------------+---------+-----------+----+-----------+| ubuntu08 | 192.168.152.115:9000 | Replica | streaming |  3 |         0 || ubuntu09 | 192.168.152.116:9000 | Leader  | running   |  3 |           || ubuntu10 | 192.168.152.117:9000 | Replica | streaming |  3 |         0 |+----------+----------------------+---------+-----------+----+-----------+root@ubuntu08:/usr/local/pgsql16/patroni#root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml switchoverCurrent cluster topology+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+| Member   | Host                 | Role    | State     | TL | Lag in MB |+----------+----------------------+---------+-----------+----+-----------+| ubuntu08 | 192.168.152.115:9000 | Replica | streaming |  3 |         0 || ubuntu09 | 192.168.152.116:9000 | Leader  | running   |  3 |           || ubuntu10 | 192.168.152.117:9000 | Replica | streaming |  3 |         0 |+----------+----------------------+---------+-----------+----+-----------+Primary [ubuntu09]:																							#1，这里是提示当前主节点为Ubuntu09，不需要任何输入，回车即可Candidate ['ubuntu08', 'ubuntu10'] []: ubuntu08																#2，这里列举出2个从节点，可以选择输入其中一个从节点提升为主节点，也可以不选择（默认选择）When should the switchover take place (e.g. 2025-09-26T09:08 )  [now]:										#3，提示当前直接执行切换，回车即可Are you sure you want to switchover cluster pg_cluster_wy_prod, demoting current leader ubuntu09? [y/N]: y	#4，输入y确认执行2025-09-26 08:09:02.30730 Successfully switched over to "ubuntu08"+ Cluster: pg_cluster_wy_prod (7553485872297570126) --+----+-----------+| Member   | Host                 | Role    | State   | TL | Lag in MB |+----------+----------------------+---------+---------+----+-----------+| ubuntu08 | 192.168.152.115:9000 | Leader  | running |  3 |           || ubuntu09 | 192.168.152.116:9000 | Replica | stopped |    |   unknown || ubuntu10 | 192.168.152.117:9000 | Replica | running |  3 |         0 |+----------+----------------------+---------+---------+----+-----------+root@ubuntu08:/usr/local/pgsql16/patroni#root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml list+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+| Member   | Host                 | Role    | State     | TL | Lag in MB |+----------+----------------------+---------+-----------+----+-----------+| ubuntu08 | 192.168.152.115:9000 | Leader  | running   |  4 |           || ubuntu09 | 192.168.152.116:9000 | Replica | streaming |  4 |         0 || ubuntu10 | 192.168.152.117:9000 | Replica | streaming |  4 |         0 |+----------+----------------------+---------+-----------+----+-----------+root@ubuntu08:/usr/local/pgsql16/patroni#

6.2 patonictl failover 

patonictl failover 允许在没有健康节点时执行手动 failover ，也就是节点故障了，不能switchover了，只能用failover来切换 。patronictl failover允许在集群中的任意节点执行切换操作

root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml failoverCurrent cluster topology+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+| Member   | Host                 | Role    | State     | TL | Lag in MB |+----------+----------------------+---------+-----------+----+-----------+| ubuntu08 | 192.168.152.115:9000 | Leader  | running   |  4 |           || ubuntu09 | 192.168.152.116:9000 | Replica | streaming |  4 |         0 || ubuntu10 | 192.168.152.117:9000 | Replica | streaming |  4 |         0 |+----------+----------------------+---------+-----------+----+-----------+Candidate ['ubuntu09', 'ubuntu10'] []: ubuntu10																	#1：这里列举出来从节点，输入从节点主机名Are you sure you want to failover cluster pg_cluster_wy_prod, demoting current leader ubuntu08? [y/N]: y		#2：这里输入y，执行切换确认2025-09-26 08:15:47.24592 Successfully failed over to "ubuntu10"+ Cluster: pg_cluster_wy_prod (7553485872297570126) --+----+-----------+| Member   | Host                 | Role    | State   | TL | Lag in MB |+----------+----------------------+---------+---------+----+-----------+| ubuntu08 | 192.168.152.115:9000 | Replica | stopped |    |   unknown || ubuntu09 | 192.168.152.116:9000 | Replica | running |  4 |         0 || ubuntu10 | 192.168.152.117:9000 | Leader  | running |  4 |           |+----------+----------------------+---------+---------+----+-----------+root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml list+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+| Member   | Host                 | Role    | State     | TL | Lag in MB |+----------+----------------------+---------+-----------+----+-----------+| ubuntu08 | 192.168.152.115:9000 | Replica | stopped   |    |   unknown || ubuntu09 | 192.168.152.116:9000 | Replica | streaming |  4 |         0 || ubuntu10 | 192.168.152.117:9000 | Leader  | running   |  5 |           |+----------+----------------------+---------+-----------+----+-----------+root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml list+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+| Member   | Host                 | Role    | State     | TL | Lag in MB |+----------+----------------------+---------+-----------+----+-----------+| ubuntu08 | 192.168.152.115:9000 | Replica | streaming |  5 |         0 || ubuntu09 | 192.168.152.116:9000 | Replica | streaming |  5 |         0 || ubuntu10 | 192.168.152.117:9000 | Leader  | running   |  5 |           |+----------+----------------------+---------+-----------+----+-----------+root@ubuntu08:/usr/local/pgsql16/patroni#

7，重启PostgreSQL实例

patronictl -c /usr/local/pgsql16/patroni/patroni.yml restart cluster_name（集群名） hostname（主机名）

root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml restart pg_cluster_wy_prod ubuntu08+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+| Member   | Host                 | Role    | State     | TL | Lag in MB |+----------+----------------------+---------+-----------+----+-----------+| ubuntu08 | 192.168.152.115:9000 | Replica | streaming |  5 |         0 || ubuntu09 | 192.168.152.116:9000 | Replica | streaming |  5 |         0 || ubuntu10 | 192.168.152.117:9000 | Leader  | running   |  5 |           |+----------+----------------------+---------+-----------+----+-----------+When should the restart take place (e.g. 2025-09-26T09:20)  [now]:Are you sure you want to restart members ubuntu08? [y/N]: yRestart if the PostgreSQL version is less than provided (e.g. 9.5.2)  []:Success: restart on member ubuntu08root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml list+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+| Member   | Host                 | Role    | State     | TL | Lag in MB |+----------+----------------------+---------+-----------+----+-----------+| ubuntu08 | 192.168.152.115:9000 | Replica | streaming |  5 |         0 || ubuntu09 | 192.168.152.116:9000 | Replica | streaming |  5 |         0 || ubuntu10 | 192.168.152.117:9000 | Leader  | running   |  5 |           |+----------+----------------------+---------+-----------+----+-----------+root@ubuntu08:/usr/local/pgsql16/patroni#

8，重新加载patroni的配置文件

在修改patroni的参数的时候，类似于PostgreSQL中执行select pg_reload_conf()，需要重新加载参数，patronictl -c /usr/local/pgsql16/patroni/patroni.yml reload pg_cluster_wy_prod

root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml reload pg_cluster_wy_prod+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+| Member   | Host                 | Role    | State     | TL | Lag in MB |+----------+----------------------+---------+-----------+----+-----------+| ubuntu08 | 192.168.152.115:9000 | Replica | streaming |  5 |         0 || ubuntu09 | 192.168.152.116:9000 | Replica | streaming |  5 |         0 || ubuntu10 | 192.168.152.117:9000 | Leader  | running   |  5 |           |+----------+----------------------+---------+-----------+----+-----------+Are you sure you want to reload members ubuntu08, ubuntu09, ubuntu10? [y/N]: yReload request received for member ubuntu08 and will be processed within 10 secondsReload request received for member ubuntu09 and will be processed within 10 secondsReload request received for member ubuntu10 and will be processed within 10 secondsroot@ubuntu08:/usr/local/pgsql16/patroni#

9，重新初始化节点

当从节点损坏，需要重新初始化的情况下，执行命令为patronictl reinit pg_cluster_wy_prod。
任意节点上执行，会删除（需要初始化的）输入的从节点的数据目录，然后重新从主节点初始化PostgreSQL实例

root@ubuntu08:/usr/local/pgsql16/patroni#root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml reinit pg_cluster_wy_prod+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+| Member   | Host                 | Role    | State     | TL | Lag in MB |+----------+----------------------+---------+-----------+----+-----------+| ubuntu08 | 192.168.152.115:9000 | Replica | streaming |  5 |         0 || ubuntu09 | 192.168.152.116:9000 | Replica | streaming |  5 |         0 || ubuntu10 | 192.168.152.117:9000 | Leader  | running   |  5 |           |+----------+----------------------+---------+-----------+----+-----------+Which member do you want to reinitialize [ubuntu09, ubuntu08]? []: ubuntu08    #输入需要重新初始化的主机Are you sure you want to reinitialize members ubuntu08? [y/N]: y               #确认Success: reinitialize for member ubuntu08root@ubuntu08:/usr/local/pgsql16/patroni#root@ubuntu08:/usr/local/pgsql16/patroni# patronictl -c /usr/local/pgsql16/patroni/patroni.yml list+ Cluster: pg_cluster_wy_prod (7553485872297570126) ----+----+-----------+| Member   | Host                 | Role    | State     | TL | Lag in MB |+----------+----------------------+---------+-----------+----+-----------+| ubuntu08 | 192.168.152.115:9000 | Replica | streaming |  5 |         0 || ubuntu09 | 192.168.152.116:9000 | Replica | streaming |  5 |         0 || ubuntu10 | 192.168.152.117:9000 | Leader  | running   |  5 |           |+----------+----------------------+---------+-----------+----+-----------+root@ubuntu08:/usr/local/pgsql16/patroni#root@ubuntu08:/usr/local/pgsql16/patroni#