PostgreSQL pg_auto_failover 高可用 1：pg_auto_failover集群搭建
0，pg_auto_failover架构
开始之前，先看一下pg_auto_failover的一个最基础架构原理如下，需要弄清楚几个节点的作用
1，monitor节点的身份是一个监控节点，仅存储元数据，负责监控primary和secondary的健康状况以及异常情况下的故障转移。
2，monitor不负责存储用户数据，负责存储用户数据的是primary和secondary节点。
3，monitor节点是一个单点，存在单点故障的可能性，这是pg_auto_failover的硬伤，但monitor节点故障后不影响primary和secondary的运行。
4，primary和secondary节点是用户数据库的存储节点，先注册到monitor中的节点为主节点，后注册到monitor的节点为从节点，正常注册后实现流复制，其身份可以互换。
1，环境准备
1.1 主机环境
Ubuntu 20，三台机器均已安装好PostgreSQL 16.4版本数据库monitor： 192.168.152.121 ubuntu11
主： 192.168.152.122 ubuntu12
从： 192.168.152.123 ubuntu131.2 三台主机同步修改，操作一致
vi /etc/hosts
192.168.152.121 ubuntu11
192.168.152.122 ubuntu12
192.168.152.123 ubuntu131.3 设置环境变量
--配置postgres的环境变量
vi /etc/profile
export LANG=en_US.utf8
export PGDATA=/usr/local/pgsql16/pg9300/data/
export PGHOME=/usr/local/pgsql16/server
export PATH=/usr/local/pgsql16/server/bin:$PATH
export LD_LIBRARY_PATH=/usr/local/pgsql16/server/lib 2，pg_auto_failover源码编译安装
2.1 下载源码包，编译安装
三个节点都要安装，这里仅以Ubuntu11上的安装为示例--下载pg_auto_failover源码包
cd /usr/local/pg_auto_failover
wget https://github.com/hapostgres/pg_auto_failover/archive/refs/tags/v2.2.zip
apt install unzip
unzip v2.2.zip
--解压后路径如下
drwxr-xr-x3 root root 4096 Jun4 16:27 ./
drwxr-xr-x 14 root root 4096 Jun4 16:26 ../
drwxr-xr-x8 root root 4096 Apr3 20:05 pg_auto_failover-2.2/
-rw-r--r--1 root root 1364027 Jun4 16:26 v2.2.zip
--这里的安装，实际上将pg_auto_failover的编译文件，安装到上面配置postgres的环境变量的指定的路径中
cd pg_auto_failover-2.2/
make
make install
--安装完成后，重新将PGHOME相关目录授权给postgres用户，否则后续使用pg_autoctl的时候会报找不到命令的错误
chown -R postgres:postgres /usr/local/pgsql16/2.2 编译安装的pg_auto_failover位置
实际上pg_auto_failover的编译安装之后，把文件存放在上述环境变量的PGHOME=/usr/local/pgsql16/server目录的bin和lib目录下
3，monitor节点配置pg_auto_failover
3.1 pg_auto_failover初始化
原实例是自动安装的，初始化了data目录，这里需要停止原实例，并且需要将data目录清理干净，需要切换到postgres用户下执行pg_autoctl create monitor --pgdata /usr/local/pgsql16/pg9300/data/ --auth trust --ssl-self-signed --hostname ubuntu11 --pgport 9300 --run1，这里加上pgdata和pgport等参数，不加的话pgdata从上面设置的环境变量中获取，端口号为默认的54322，加上 --run会非后台的方式自动运行pg_auto_failover实例，没必要加3，--hostname 要用主机名，不能用IP 遇到的问题：1，ERROR Failed to create state directory "/run/user/0/pg_autoctl": Permission denied root@ubuntu11:/usr/local/pg_install_packgae# sudo chmod -R 777 /run/user/0 root@ubuntu11:/usr/local/pg_install_packgae# sudo chown -R postgres:postgres /run/user/02，pg_autoctl: command not found source /etc/profile错误如下postgres@ubuntu11:/usr/local/pg_install_packgae$ pg_autoctl create monitor --pgdata /usr/local/pgsql16/pg9300/data/--auth trust--ssl-self-signed --hostname ubuntu11--pgport 9300
pg_autoctl: command not found
postgres@ubuntu11:/usr/local/pg_install_packgae$
postgres@ubuntu11:/usr/local/pg_install_packgae$
postgres@ubuntu11:/usr/local/pg_install_packgae$ /usr/local/pgsql16/server/bin/pg_autoctl create monitor --pgdata /usr/local/pgsql16/pg9300/data/--auth trust--ssl-self-signed --hostname 127.0.0.1--pgport 9300
10:47:45 2821 ERROR Failed to create state directory "/run/user/0/pg_autoctl": Permission denied
10:47:45 2821 ERROR Failed to build pg_autoctl pid file pathname, see above.
10:47:45 2821 FATAL Failed to set pid filename from PGDATA "/usr/local/pgsql16/pg9300/data/", see above for details.
postgres@ubuntu11:/usr/local/pg_install_packgae$
postgres@ubuntu11:/usr/local/pg_install_packgae$
postgres@ubuntu11:/usr/local/pg_install_packgae$ exit
exit
root@ubuntu11:/usr/local/pg_install_packgae# sudo chmod -R 777 /run/user/0
root@ubuntu11:/usr/local/pg_install_packgae# sudo chown -R postgres:postgres /run/user/0
root@ubuntu11:/usr/local/pg_install_packgae#修复后正常初始化monitor节点root@ubuntu11:/usr/local/pg_install_packgae# su - postgres #切换到postgres用户下执行
postgres@ubuntu11:~$
postgres@ubuntu11:~$
postgres@ubuntu11:~$
postgres@ubuntu11:~$ pg_autoctl create monitor --pgdata /usr/local/pgsql16/pg9300/data/--auth trust--ssl-self-signed --hostname ubuntu11--pgport 9300 --run
05:04:27 2216 INFOUsing default --ssl-mode "require"
05:04:27 2216 INFOUsing --ssl-self-signed: pg_autoctl will create self-signed certificates, allowing for encrypted network traffic
05:04:27 2216 WARNSelf-signed certificates provide protection against eavesdropping; this setup does NOT protect against Man-In-The-Middle attacks nor Impersonation attacks.
05:04:27 2216 WARNSee https://www.postgresql.org/docs/current/libpq-ssl.html for details
05:04:27 2216 INFOInitialising a PostgreSQL cluster at "/usr/local/pgsql16/pg9300/data"
05:04:27 2216 INFO/usr/local/pgsql16/server/bin/pg_ctl initdb -s -D /usr/local/pgsql16/pg9300/data --option '--auth=trust'
05:04:29 2216 INFO /usr/bin/openssl req -new -x509 -days 365 -nodes -text -out /usr/local/pgsql16/pg9300/data/server.crt -keyout /usr/local/pgsql16/pg9300/data/server.key -subj "/CN=ubuntu11"
05:04:29 2216 INFOStarted pg_autoctl postgres service with pid 2238
05:04:29 2216 INFOStarted pg_autoctl listener service with pid 2239
05:04:29 2238 INFO /usr/local/pgsql16/server/bin/pg_autoctl do service postgres --pgdata /usr/local/pgsql16/pg9300/data/ -v
05:04:29 2243 INFO /usr/local/pgsql16/server/bin/postgres -D /usr/local/pgsql16/pg9300/data -p 9300 -h *
05:04:29 2238 INFOPostgres is now serving PGDATA "/usr/local/pgsql16/pg9300/data" on port 9300 with pid 2243
05:04:29 2239 WARNNOTICE:installing required extension "btree_gist"
05:04:29 2239 INFOGranting connection privileges on 192.168.152.0/24
05:04:29 2239 WARNSkipping HBA edits (per --skip-pg-hba) for rule: hostssl "pg_auto_failover" "autoctl_node" 192.168.152.0/24 trust
05:04:29 2239 INFOYour pg_auto_failover monitor instance is now ready on port 9300.
05:04:29 2239 INFOMonitor has been successfully initialized.
05:04:29 2239 INFO /usr/local/pgsql16/server/bin/pg_autoctl do service listener --pgdata /usr/local/pgsql16/pg9300/data/ -v
05:04:29 2239 INFOManaging the monitor at postgres://autoctl_node@ubuntu11:9300/pg_auto_failover?sslmode=require
05:04:29 2239 INFOReloaded the new configuration from "/home/postgres/.config/pg_autoctl/usr/local/pgsql16/pg9300/data/pg_autoctl.cfg"
05:04:29 2239 INFOReloading Postgres configuration and HBA rules
05:04:30 2239 INFOThe version of extension "pgautofailover" is "2.2" on the monitor
05:04:30 2239 INFOContacting the monitor to LISTEN to its events.3.2 pg_auto_failover systemctl脚本配置
切换到root用户下执行pg_autoctl show systemd，会打印出来生成的systemctl命令以及自动启动命令，执行如下4条命令即可pg_autoctl -q show systemd --pgdata "/usr/local/pgsql16/pg9300/data" | tee /etc/systemd/system/pgautofailover.servicesystemctl daemon-reloadsystemctl enable pgautofailoversystemctl start pgautofailoverpostgres@ubuntu11:~$ exit #切换到root用户执行
logout
root@ubuntu11:/usr/local/pg_install_packgae# pg_autoctl show systemd
05:06:26 2333 INFOHINT: to complete a systemd integration, run the following commands (as root):
05:06:26 2333 INFOpg_autoctl -q show systemd --pgdata "/usr/local/pgsql16/pg9300/data" | tee /etc/systemd/system/pgautofailover.service
05:06:26 2333 INFOsystemctl daemon-reload
05:06:26 2333 INFOsystemctl enable pgautofailover
05:06:26 2333 INFOsystemctl start pgautofailover
Description = pg_auto_failover
WorkingDirectory = /home/postgres
Environment = 'PGDATA=/usr/local/pgsql16/pg9300/data'
User = postgres
ExecStart = /usr/local/pgsql16/server/bin/pg_autoctl run
Restart = always
StartLimitBurst = 0
ExecReload = /usr/local/pgsql16/server/bin/pg_autoctl reload
WantedBy = multi-user.target
root@ubuntu11:/usr/local/pg_install_packgae#
root@ubuntu11:/usr/local/pg_install_packgae#
root@ubuntu11:/usr/local/pg_install_packgae# pg_autoctl -q show systemd --pgdata "/usr/local/pgsql16/pg9300/data" | tee /etc/systemd/system/pgautofailover.service
Description = pg_auto_failover
WorkingDirectory = /home/postgres
Environment = 'PGDATA=/usr/local/pgsql16/pg9300/data'
User = postgres
ExecStart = /usr/local/pgsql16/server/bin/pg_autoctl run
Restart = always
StartLimitBurst = 0
ExecReload = /usr/local/pgsql16/server/bin/pg_autoctl reload
WantedBy = multi-user.target
root@ubuntu11:/usr/local/pg_install_packgae#
root@ubuntu11:/usr/local/pg_install_packgae# systemctl daemon-reload
root@ubuntu11:/usr/local/pg_install_packgae#
root@ubuntu11:/usr/local/pg_install_packgae# systemctl enable pgautofailover
Created symlink /etc/systemd/system/multi-user.target.wants/pgautofailover.service → /etc/systemd/system/pgautofailover.service.
root@ubuntu11:/usr/local/pg_install_packgae#
root@ubuntu11:/usr/local/pg_install_packgae# systemctl start pgautofailover
root@ubuntu11:/usr/local/pg_install_packgae#
root@ubuntu11:/usr/local/pg_install_packgae# systemctl status pgautofailover
● pgautofailover.service - pg_auto_failover
Loaded: loaded (/etc/systemd/system/pgautofailover.service; enabled; vendor preset: enabled)
Active: active (running) since Thu 2025-10-09 05:06:43 UTC; 5s ago
Main PID: 2421 (pg_autoctl)
Tasks: 14 (limit: 4550)
Memory: 29.2M
CGroup: /system.slice/pgautofailover.service
├─2421 /usr/local/pgsql16/server/bin/pg_autoctl run
├─2444 pg_autoctl: start/stop postgres
├─2445 pg_autoctl: monitor listener
├─2454 /usr/local/pgsql16/server/bin/postgres -D /usr/local/pgsql16/pg9300/data -p 9300 -h *
├─2455 postgres: pg_auto_failover monitor: logger
├─2456 postgres: pg_auto_failover monitor: checkpointer
├─2457 postgres: pg_auto_failover monitor: background writer
├─2459 postgres: pg_auto_failover monitor: walwriter
├─2460 postgres: pg_auto_failover monitor: autovacuum launcher
├─2461 postgres: pg_auto_failover monitor: pg_auto_failover monitor
├─2462 postgres: pg_auto_failover monitor: logical replication launcher
├─2463 postgres: pg_auto_failover monitor: pg_auto_failover monitor healthcheck worker postgres
├─2464 postgres: pg_auto_failover monitor: pg_auto_failover monitor healthcheck worker pg_auto_failover
└─2466 postgres: pg_auto_failover monitor: autoctl_node pg_auto_failover idle
Oct 09 05:06:43 ubuntu11 pg_autoctl: 05:06:43 2421 INFOStarted pg_autoctl postgres service with pid 2444
Oct 09 05:06:43 ubuntu11 pg_autoctl: 05:06:43 2421 INFOStarted pg_autoctl listener service with pid 2445
Oct 09 05:06:43 ubuntu11 pg_autoctl: 05:06:43 2445 INFO /usr/local/pgsql16/server/bin/pg_autoctl do service listener --pgdata /usr/local/pgsql16/pg9300/data -v
Oct 09 05:06:43 ubuntu11 pg_autoctl: 05:06:43 2444 INFO /usr/local/pgsql16/server/bin/pg_autoctl do service postgres --pgdata /usr/local/pgsql16/pg9300/data -v
Oct 09 05:06:43 ubuntu11 pg_autoctl: 05:06:43 2445 INFOManaging the monitor at postgres://autoctl_node@ubuntu11:9300/pg_auto_failover?sslmode=require
Oct 09 05:06:43 ubuntu11 pg_autoctl: 05:06:43 2445 INFOReloaded the new configuration from "/home/postgres/.config/pg_autoctl/usr/local/pgsql16/pg9300/data/pg_autoctl.cfg"
Oct 09 05:06:43 ubuntu11 pg_autoctl: 05:06:43 2454 INFO /usr/local/pgsql16/server/bin/postgres -D /usr/local/pgsql16/pg9300/data -p 9300 -h *
Oct 09 05:06:43 ubuntu11 pg_autoctl: 05:06:43 2444 INFOPostgres is now serving PGDATA "/usr/local/pgsql16/pg9300/data" on port 9300 with pid 2454
Oct 09 05:06:43 ubuntu11 pg_autoctl: 05:06:43 2445 INFOThe version of extension "pgautofailover" is "2.2" on the monitor
Oct 09 05:06:43 ubuntu11 pg_autoctl: 05:06:43 2445 INFOContacting the monitor to LISTEN to its events.
root@ubuntu11:/usr/local/pg_install_packgae#执行完上述命令后，已正常启动pg_auto_failover的monitor节点。 3.3 pg_auto_failover 初始化验证
monitor节点初始化的数据文件如下，此时monitor节点使用的配置文件是postgresql-auto-failover.conf，而不是单机安装使用的postgresql.conf查看初始化的库和相关角色对象root@ubuntu11:/usr/local/pg_install_packgae# psql -h ubuntu11 -p 9300 postgres postgres
psql (16.4)
SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, compression: off)
Type "help" for help.
#1，自动安装了pg_auto_failover库
postgres=# \l
List of databases
Name |Owner | Encoding | Locale Provider |Collate | Ctype | ICU Locale | ICU Rules | Access privileges
------------------+----------+----------+-----------------+------------+------------+------------+-----------+-----------------------
pg_auto_failover | autoctl| UTF8 | libc | en_US.utf8 | en_US.utf8 | | |
postgres | postgres | UTF8 | libc | en_US.utf8 | en_US.utf8 | | |
template0 | postgres | UTF8 | libc | en_US.utf8 | en_US.utf8 | | | =c/postgres +
| | | | | | | | postgres=CTc/postgres
template1 | postgres | UTF8 | libc | en_US.utf8 | en_US.utf8 | | | =c/postgres +
| | | | | | | | postgres=CTc/postgres
(4 rows)
#2，自动创建了autoctl和autoctl_node两个角色
postgres=# \du
List of roles
Role name | Attributes
--------------+------------------------------------------------------------
autoctl |
autoctl_node |
postgres | Superuser, Create role, Create DB, Replication, Bypass RLS
#3，自动安装了如下两个扩展
postgres=# \c pg_auto_failover
SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, compression: off)
You are now connected to database "pg_auto_failover" as user "postgres".
pg_auto_failover=# \dx
List of installed extensions
Name | Version | Schema | Description
----------------+---------+------------+-----------------------------------------------
btree_gist | 1.7 | public | support for indexing common datatypes in GiST
pgautofailover | 2.2 | public | pg_auto_failover
plpgsql | 1.0 | pg_catalog | PL/pgSQL procedural language
(3 rows)
pg_auto_failover=# 查看monitor节点的连接串，主从节点加入pg_auto_failover的时候会用到这个连接串root@ubuntu11:/usr/local/pg_install_packgae#
root@ubuntu11:/usr/local/pg_install_packgae#
root@ubuntu11:/usr/local/pg_install_packgae# pg_autoctl show uri
Type | Name | Connection String
-------------+---------+-------------------------------
monitor | monitor | postgres://autoctl_node@127.0.0.1:9300/pg_auto_failover?sslmode=require #一开始我懵逼了，为什么连接串里是127.0.0.1
formation | default |
root@ubuntu11:/usr/local/pg_install_packgae# su - postgres
postgres@ubuntu11:~$
postgres@ubuntu11:~$ source /etc/profile
postgres@ubuntu11:~$
postgres@ubuntu11:~$ pg_autoctl show uri
Type | Name | Connection String
-------------+---------+-------------------------------
monitor | monitor | postgres://autoctl_node@Ubuntu11:9300/pg_auto_failover?sslmode=require #后来尝试切换到postgres用户下查看，竟然变成了主机名，搞什么鬼哦
formation | default |
postgres@ubuntu11:~$ 4，主节点和从节点依次加入pg_auto_failover集群
主从节点上1，因为PostgreSQL实例是自动化安装的，初始化了数据库，这里需要停止PostgreSQL实例的服务，并且删除相关的pgdata2，因为PostgreSQL服务已经交由pg_auto_failover托管，由pg_auto_failover来启动，所以务必禁用PostgreSQL自身的自动启动服务3，2中提到了，主从以及monitor节点都要安装pg_auto_failover，这里所有节点都已经安装了pg_auto_failover 4.1 注册主节点中遇到的异常处理
注册命令：pg_autoctl create postgres --hostname ubuntu12 --name ubuntu12 --auth trust --ssl-self-signed --pgdata /usr/local/pgsql16/pg9300/data/ --pgport 9300 --monitor 'postgres://autoctl_node@Ubuntu11:9300/pg_auto_failover?sslmode=require'1，注意，Ubuntu下一定要切换到postgres下执行2，执行注册主节点命令，但是不很不幸，报错了解决办法：1，修改monitor节点的hba.conf文件，增加受信任链接配置：host all all 192.168.152.0/24 trust2，重启monitor节点，systemctl restart pgautofailover 然后又报错，切换到root下执行chmod -R 777 /run/user/0chown -R postgres:postgres /run/user/0postgres@ubuntu12:/root$ pg_autoctl create postgres --hostname ubuntu12 --name ubuntu12 --auth trust --ssl-self-signed --pgdata /usr/local/pgsql16/pg9300/data/ --pgport 9300 --monitor 'postgres://autoctl_node@Ubuntu11:9300/pg_auto_failover?sslmode=require'
03:09:00 58370 ERROR Failed to create state directory "/run/user/0/pg_autoctl": Permission denied
03:09:00 58370 ERROR Failed to build pg_autoctl pid file pathname, see above.
03:09:00 58370 FATAL Failed to set pid filename from PGDATA "/usr/local/pgsql16/pg9300/data/", see above for details.
postgres@ubuntu12:/root$
postgres@ubuntu12:/root$
postgres@ubuntu12:/root$ exit
exit
root@ubuntu12:~# sudo chmod -R 777 /run/user/0
root@ubuntu12:~# sudo chown -R postgres:postgres /run/user/0 对于错误清理，由于各种原因，第一次初始化失败的话，需要完成以下两步操作才能“重置”，否则会报各种各样的错误，这里批评一下pg_auto_failover，报错信息太乱了，笔者在这里卡了很久，尝试了很久弄清楚这个地方的坑。 1，直接从monitor节点的数据库pgautofailover.node中删除注册的节点，参考如下root@ubuntu11:/usr/local/pg_install_packgae# psql -h 127.0.0.1 -p 9300 postgres postgres
psql (16.4)
SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, compression: off)
Type "help" for help.
postgres=# \c pg_auto_failover
SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, compression: off)
You are now connected to database "pg_auto_failover" as user "postgres".
pg_auto_failover=#
pg_auto_failover=# SELECT nodeid, nodename, nodehost, nodeport, goalstate, reportedstate FROM pgautofailover.node;
nodeid | nodename | nodehost | nodeport | goalstate | reportedstate
--------+----------+----------+----------+-----------+---------------
1 | ubuntu12 | ubuntu12 | 9300 | single | single
(1 row)
pg_auto_failover=# delete frompgautofailover.node where nodeid = 1;
DELETE 1
pg_auto_failover=#
pg_auto_failover=#
root@ubuntu11:/usr/local/pg_install_packgae# su - postgres
postgres@ubuntu11:~$
postgres@ubuntu11:~$ source /etc/profile
postgres@ubuntu11:~$
postgres@ubuntu11:~$ pg_autoctl show uri #这样monitor节点恢复成原始状态，解决错误后再重新注册主/从节点
Type | Name | Connection String
-------------+---------+-------------------------------
monitor | monitor | postgres://autoctl_node@Ubuntu11:9300/pg_auto_failover?sslmode=require
formation | default |
postgres@ubuntu11:~$这一点非常扯淡，pg_autoctl在注册一个节点的时候，先把元数据写入monitor节点的pg_auto_failover数据库，然后（主节点）拉取数据，或者（从节点）备份数据，如果后一个东西失败，节点信息还是回注册到monitor库中，后续就需要手动删除节点信息。 2，清理 pg_autoctl 状态文件
本地清理 keeper state，再强制注册
本地 pg_autoctl 会维护一个状态文件（通常在 ~/.local/share/pg_autoctl/.../pg_autoctl.state）。
如果你只是清理 pgdata，但没有清理这个文件，再次注册会冲突。
解决：
rm -rf /home/postgres/.local/share/pg_autoctl
然后重新运行 pg_autoctl create，这样它会认为是一个全新节点。
4.2 注册主节点
再次注册主节点，这次可以了，注册主节点命令如下
/usr/local/pgsql16/server/bin/pg_autoctl create postgres \
--hostname ubuntu12 \
--name ubuntu12 \
--pgport 9300 \
--auth trust \
--ssl-self-signed \
--monitor 'postgres://autoctl_node@ubuntu11:9300/pg_auto_failover?sslmode=require'root@ubuntu12:~# su - postgres
postgres@ubuntu12:~$
postgres@ubuntu12:~$
postgres@ubuntu12:~$
postgres@ubuntu12:~$
postgres@ubuntu12:~$ pg_autoctl create postgres --hostname ubuntu12 --name ubuntu12 --auth trust --ssl-self-signed --pgdata /usr/local/pgsql16/pg9300/data/ --pgport 9300 --monitor 'postgres://autoctl_node@Ubuntu11:9300/pg_auto_failover?sslmode=require'
05:17:27 2094 INFOUsing default --ssl-mode "require"
05:17:27 2094 INFOUsing --ssl-self-signed: pg_autoctl will create self-signed certificates, allowing for encrypted network traffic
05:17:27 2094 WARNSelf-signed certificates provide protection against eavesdropping; this setup does NOT protect against Man-In-The-Middle attacks nor Impersonation attacks.
05:17:27 2094 WARNSee https://www.postgresql.org/docs/current/libpq-ssl.html for details
05:17:27 2094 INFOStarted pg_autoctl postgres service with pid 2096
05:17:27 2094 INFOStarted pg_autoctl node-init service with pid 2097
05:17:27 2096 INFO /usr/local/pgsql16/server/bin/pg_autoctl do service postgres --pgdata /usr/local/pgsql16/pg9300/data/ -v
05:17:27 2097 INFORegistered node 52 "ubuntu12" (ubuntu12:9300) in formation "default", group 0, state "single"
05:17:27 2097 INFOWriting keeper state file at "/home/postgres/.local/share/pg_autoctl/usr/local/pgsql16/pg9300/data/pg_autoctl.state"
05:17:27 2097 INFOWriting keeper init state file at "/home/postgres/.local/share/pg_autoctl/usr/local/pgsql16/pg9300/data/pg_autoctl.init"
05:17:27 2097 INFOSuccessfully registered as "single" to the monitor.
05:17:27 2097 INFOFSM transition from "init" to "single": Start as a single node
05:17:27 2097 INFOInitialising postgres as a primary
05:17:27 2097 INFOInitialising a PostgreSQL cluster at "/usr/local/pgsql16/pg9300/data"
05:17:27 2097 INFO/usr/local/pgsql16/server/bin/pg_ctl initdb -s -D /usr/local/pgsql16/pg9300/data --option '--auth=trust'
05:17:27 2097 INFO /usr/bin/openssl req -new -x509 -days 365 -nodes -text -out /usr/local/pgsql16/pg9300/data/server.crt -keyout /usr/local/pgsql16/pg9300/data/server.key -subj "/CN=ubuntu12"
05:17:28 2122 INFO /usr/local/pgsql16/server/bin/postgres -D /usr/local/pgsql16/pg9300/data -p 9300 -h *
05:17:28 2096 INFOPostgres is now serving PGDATA "/usr/local/pgsql16/pg9300/data" on port 9300 with pid 2122
05:17:28 2097 INFOThe user "postgres" already exists, skipping.
05:17:28 2097 INFOCREATE USER postgres
05:17:28 2097 INFOCREATE DATABASE postgres;
05:17:28 2097 INFOThe database "postgres" already exists, skipping.
05:17:28 2097 INFOCREATE EXTENSION pg_stat_statements;
05:17:28 2097 INFODisabling synchronous replication
05:17:28 2097 INFOReloading Postgres configuration and HBA rules
05:17:28 2097 WARNFailed to resolve hostname "Ubuntu11" to an IP address that resolves back to the hostname on a reverse DNS lookup.
05:17:28 2097 WARNPostgres might deny connection attempts from "Ubuntu11", even with the new HBA rules.
05:17:28 2097 WARNHint: correct setup of HBA with host names requires proper reverse DNS setup. You might want to use IP addresses.
05:17:28 2097 WARNUsing IP address "192.168.152.121" in HBA file instead of hostname "Ubuntu11"
05:17:28 2097 INFOReloading Postgres configuration and HBA rules
05:17:28 2097 INFOTransition complete: current state is now "single"
05:17:28 2097 INFOkeeper has been successfully initialized.
05:17:28 2094 WARNpg_autoctl service node-init exited with exit status 0
05:17:28 2096 INFOPostgres controller service received signal SIGTERM, terminating
05:17:28 2096 INFOStopping pg_autoctl postgres service
05:17:28 2096 INFO/usr/local/pgsql16/server/bin/pg_ctl --pgdata /usr/local/pgsql16/pg9300/data --wait stop --mode fast
05:17:28 2094 INFOStop pg_autoctl
postgres@ubuntu12:~$初始化主节点systemctl服务，切换到root用户下执行pg_autoctl show systemd然后依次执行如下命令即可pg_autoctl -q show systemd --pgdata "/usr/local/pgsql16/pg9300/data" | tee /etc/systemd/system/pgautofailover.servicesystemctl daemon-reloadsystemctl enable pgautofailoversystemctl start pgautofailoverpostgres@ubuntu12:~$
postgres@ubuntu12:~$ exit
logout
root@ubuntu12:~# pg_autoctlshow systemd
05:18:06 2160 INFOHINT: to complete a systemd integration, run the following commands (as root):
05:18:06 2160 INFOpg_autoctl -q show systemd --pgdata "/usr/local/pgsql16/pg9300/data" | tee /etc/systemd/system/pgautofailover.service
05:18:06 2160 INFOsystemctl daemon-reload
05:18:06 2160 INFOsystemctl enable pgautofailover
05:18:06 2160 INFOsystemctl start pgautofailover
Description = pg_auto_failover
WorkingDirectory = /home/postgres
Environment = 'PGDATA=/usr/local/pgsql16/pg9300/data'
User = postgres
ExecStart = /usr/local/pgsql16/server/bin/pg_autoctl run
Restart = always
StartLimitBurst = 0
ExecReload = /usr/local/pgsql16/server/bin/pg_autoctl reload
WantedBy = multi-user.target
root@ubuntu12:~# pg_autoctl -q show systemd --pgdata "/usr/local/pgsql16/pg9300/data" | tee /etc/systemd/system/pgautofailover.service
Description = pg_auto_failover
WorkingDirectory = /home/postgres
Environment = 'PGDATA=/usr/local/pgsql16/pg9300/data'
User = postgres
ExecStart = /usr/local/pgsql16/server/bin/pg_autoctl run
Restart = always
StartLimitBurst = 0
ExecReload = /usr/local/pgsql16/server/bin/pg_autoctl reload
WantedBy = multi-user.target
root@ubuntu12:~# systemctl daemon-reload
root@ubuntu12:~# systemctl enable pgautofailover
Created symlink /etc/systemd/system/multi-user.target.wants/pgautofailover.service → /etc/systemd/system/pgautofailover.service.
root@ubuntu12:~#systemctl start pgautofailover
root@ubuntu12:~#
root@ubuntu12:~# systemctl status pgautofailover
● pgautofailover.service - pg_auto_failover
Loaded: loaded (/etc/systemd/system/pgautofailover.service; enabled; vendor preset: enabled)
Active: active (running) since Thu 2025-10-09 05:18:32 UTC; 10s ago
Main PID: 2250 (pg_autoctl)
Tasks: 11 (limit: 4550)
Memory: 26.8M
CGroup: /system.slice/pgautofailover.service
├─2250 /usr/local/pgsql16/server/bin/pg_autoctl run
├─2267 pg_autoctl: start/stop postgres
├─2268 pg_autoctl: node active
├─2278 /usr/local/pgsql16/server/bin/postgres -D /usr/local/pgsql16/pg9300/data -p 9300 -h *
├─2279 postgres: logger
├─2280 postgres: checkpointer
├─2281 postgres: background writer
├─2283 postgres: walwriter
├─2284 postgres: autovacuum launcher
├─2285 postgres: logical replication launcher
└─2313 postgres: postgres postgres startup
Oct 09 05:18:32 ubuntu12 pg_autoctl: 05:18:32 2250 INFOStarted pg_autoctl postgres service with pid 2267
Oct 09 05:18:32 ubuntu12 pg_autoctl: 05:18:32 2250 INFOStarted pg_autoctl node-active service with pid 2268
Oct 09 05:18:32 ubuntu12 pg_autoctl: 05:18:32 2268 INFO /usr/local/pgsql16/server/bin/pg_autoctl do service node-active --pgdata /usr/local/pgsql16/pg9300/data -v
Oct 09 05:18:32 ubuntu12 pg_autoctl: 05:18:32 2267 INFO /usr/local/pgsql16/server/bin/pg_autoctl do service postgres --pgdata /usr/local/pgsql16/pg9300/data -v
Oct 09 05:18:32 ubuntu12 pg_autoctl: 05:18:32 2268 INFOReloaded the new configuration from "/home/postgres/.config/pg_autoctl/usr/local/pgsql16/pg9300/data/pg_autoctl.cfg"
Oct 09 05:18:32 ubuntu12 pg_autoctl: 05:18:32 2268 INFOpg_autoctl service is running, current state is "single"
Oct 09 05:18:32 ubuntu12 pg_autoctl: 05:18:32 2278 INFO /usr/local/pgsql16/server/bin/postgres -D /usr/local/pgsql16/pg9300/data -p 9300 -h *
Oct 09 05:18:32 ubuntu12 pg_autoctl: 05:18:32 2268 WARNPostgreSQL was not running, restarted with pid 2278
Oct 09 05:18:33 ubuntu12 pg_autoctl: 05:18:33 2267 INFOPostgres is now serving PGDATA "/usr/local/pgsql16/pg9300/data" on port 9300 with pid 2278
Oct 09 05:18:33 ubuntu12 pg_autoctl: 05:18:33 2268 INFONew state for this node (node 52, "ubuntu12") (ubuntu12:9300): single ➜ single
root@ubuntu12:~# 4.3 monitor 节点查看已注册的主节点
此时回到monitor节点上，1，查看pg_autoctl show uri，可以看到ubuntu12节点已经注册到monitor节点2，pg_autoctl show state，可以看到ubuntu12节点是read-write状态，处于single模式root@ubuntu11:/usr/local/pg_install_packgae#
root@ubuntu11:/usr/local/pg_install_packgae# pg_autoctl show uri
Type | Name | Connection String
-------------+---------+-------------------------------
monitor | monitor | postgres://autoctl_node@127.0.0.1:9300/pg_auto_failover?sslmode=require
formation | default | postgres://ubuntu12:9300/postgres?target_session_attrs=read-write&sslmode=require
root@ubuntu11:/usr/local/pg_install_packgae#
root@ubuntu11:/usr/local/pg_install_packgae#
root@ubuntu11:/usr/local/pg_install_packgae#
root@ubuntu11:/usr/local/pg_install_packgae# pg_autoctl show state
Name |Node | Host:Port | TLI: LSN | Connection | Reported State | Assigned State
---------+-------+---------------+----------------+--------------+---------------------+--------------------
ubuntu12 | 8 | ubuntu12:9300 | 1: 0/15596F8 | read-write | single | single
root@ubuntu11:/usr/local/pg_install_packgae#
5，从节点加入pg_auto_failover
5.1 注册从节点Ubuntu13
注册命令：pg_autoctl create postgres --hostname ubuntu13 --name ubuntu13 --auth trust --ssl-self-signed --pgdata /usr/local/pgsql16/pg9300/data/ --pgport 9300 --monitor 'postgres://autoctl_node@Ubuntu11:9300/pg_auto_failover?sslmode=require'因为从节点ubuntu13是之前安装过PostgreSQL实例的，这里直接停掉服务，删掉数据文件root@ubuntu13:/usr/local/pg_install_package# systemctl stop postgresql9300
root@ubuntu13:/usr/local/pg_install_package# systemctl disable postgresql9300
root@ubuntu13:/usr/local/pg_install_package# rm -rf /usr/local/pgsql16/pg9300注册从节点成功postgres@ubuntu13:~$ pg_autoctl create postgres --hostname ubuntu13 --name ubuntu13 --auth trust --ssl-self-signed --pgdata /usr/local/pgsql16/pg9300/data/ --pgport 9300 --monitor 'postgres://autoctl_node@Ubuntu11:9300/pg_auto_failover?sslmode=require'
05:46:07 11100 INFOUsing default --ssl-mode "require"
05:46:07 11100 INFOUsing --ssl-self-signed: pg_autoctl will create self-signed certificates, allowing for encrypted network traffic
05:46:07 11100 WARNSelf-signed certificates provide protection against eavesdropping; this setup does NOT protect against Man-In-The-Middle attacks nor Impersonation attacks.
05:46:07 11100 WARNSee https://www.postgresql.org/docs/current/libpq-ssl.html for details
05:46:07 11100 INFOStarted pg_autoctl postgres service with pid 11102
05:46:07 11100 INFOStarted pg_autoctl node-init service with pid 11103
05:46:07 11102 INFO /usr/local/pgsql16/server/bin/pg_autoctl do service postgres --pgdata /usr/local/pgsql16/pg9300/data/ -v
05:46:07 11103 INFORegistered node 60 "ubuntu13" (ubuntu13:9300) in formation "default", group 0, state "wait_standby"
05:46:07 11103 INFOWriting keeper state file at "/home/postgres/.local/share/pg_autoctl/usr/local/pgsql16/pg9300/data/pg_autoctl.state"
05:46:07 11103 INFOWriting keeper init state file at "/home/postgres/.local/share/pg_autoctl/usr/local/pgsql16/pg9300/data/pg_autoctl.init"
05:46:07 11103 INFOSuccessfully registered as "wait_standby" to the monitor.
05:46:07 11103 INFOFSM transition from "init" to "wait_standby": Start following a primary
05:46:07 11103 INFOTransition complete: current state is now "wait_standby"
05:46:07 11103 INFONew state for node 52 "ubuntu12" (ubuntu12:9300): single ➜ wait_primary
05:46:07 11103 INFONew state for node 52 "ubuntu12" (ubuntu12:9300): wait_primary ➜ wait_primary
05:46:07 11103 INFOFSM transition from "wait_standby" to "catchingup": The primary is now ready to accept a standby
05:46:07 11103 INFOInitialising PostgreSQL as a hot standby
05:46:07 11103 INFO /usr/local/pgsql16/server/bin/pg_basebackup -w -d 'application_name=pgautofailover_standby_60 host=ubuntu12 port=9300 user=pgautofailover_replicator sslmode=require' --pgdata /usr/local/pgsql16/pg9300/backup/node_60 -U pgautofailover_replicator --verbose --progress --max-rate 100M --wal-method=stream --slot pgautofailover_standby_60
05:46:07 11103 INFOpg_basebackup:
05:46:07 11103 INFO
05:46:07 11103 INFOinitiating base backup, waiting for checkpoint to complete
05:46:07 11103 INFOpg_basebackup:
05:46:07 11103 INFO
05:46:07 11103 INFOcheckpoint completed
05:46:07 11103 INFOpg_basebackup:
05:46:07 11103 INFO
05:46:07 11103 INFOwrite-ahead log start point: 0/2000028 on timeline 1
05:46:07 11103 INFOpg_basebackup:
05:46:07 11103 INFO
05:46:07 11103 INFOstarting background WAL receiver
05:46:07 11103 INFO22591/22591 kB (100%), 0/1 tablespace (...backup/node_60/global/pg_control)
05:46:08 11103 INFO22591/22591 kB (100%), 1/1 tablespace
05:46:08 11103 INFOpg_basebackup: write-ahead log end point: 0/2000138
05:46:08 11103 INFOpg_basebackup: waiting for background process to finish streaming ...
05:46:08 11103 INFOpg_basebackup: syncing data to disk ...
05:46:08 11103 INFOpg_basebackup: renaming backup_manifest.tmp to backup_manifest
05:46:08 11103 INFOpg_basebackup: base backup completed
05:46:08 11103 INFOCreating the standby signal file at "/usr/local/pgsql16/pg9300/data/standby.signal", and replication setup at "/usr/local/pgsql16/pg9300/data/postgresql-auto-failover-standby.conf"
05:46:08 11103 INFO /usr/bin/openssl req -new -x509 -days 365 -nodes -text -out /usr/local/pgsql16/pg9300/data/server.crt -keyout /usr/local/pgsql16/pg9300/data/server.key -subj "/CN=ubuntu13"
05:46:08 11116 INFO /usr/local/pgsql16/server/bin/postgres -D /usr/local/pgsql16/pg9300/data -p 9300 -h *
05:46:08 11102 INFOPostgres is now serving PGDATA "/usr/local/pgsql16/pg9300/data" on port 9300 with pid 11116
05:46:08 11103 INFOPostgreSQL started on port 9300
05:46:08 11103 INFOFetched current list of 1 other nodes from the monitor to update HBA rules, including 1 changes.
05:46:08 11103 INFOEnsuring HBA rules for node 52 "ubuntu12" (ubuntu12:9300)
05:46:08 11103 INFOAdding HBA rule: hostssl replication "pgautofailover_replicator" ubuntu12 trust
05:46:08 11103 INFOAdding HBA rule: hostssl "postgres" "pgautofailover_replicator" ubuntu12 trust
05:46:08 11103 INFOWriting new HBA rules in "/usr/local/pgsql16/pg9300/data/pg_hba.conf"
05:46:08 11103 INFOReloading Postgres configuration and HBA rules
05:46:08 11103 INFOTransition complete: current state is now "catchingup"
05:46:08 11103 INFOkeeper has been successfully initialized.
05:46:08 11100 WARNpg_autoctl service node-init exited with exit status 0
05:46:08 11102 INFOPostgres controller service received signal SIGTERM, terminating
05:46:08 11102 INFOStopping pg_autoctl postgres service
05:46:08 11102 INFO/usr/local/pgsql16/server/bin/pg_ctl --pgdata /usr/local/pgsql16/pg9300/data --wait stop --mode fast
05:46:08 11100 INFOStop pg_autoctl
postgres@ubuntu13:~$设置systemctl启动服务root@ubuntu13:/usr/local/pg_install_package#pg_autoctlshow systemd
05:48:11 12172 INFOHINT: to complete a systemd integration, run the following commands (as root):
05:48:11 12172 INFOpg_autoctl -q show systemd --pgdata "/usr/local/pgsql16/pg9300/data" | tee /etc/systemd/system/pgautofailover.service
05:48:11 12172 INFOsystemctl daemon-reload
05:48:11 12172 INFOsystemctl enable pgautofailover
05:48:11 12172 INFOsystemctl start pgautofailover
Description = pg_auto_failover
WorkingDirectory = /home/postgres
Environment = 'PGDATA=/usr/local/pgsql16/pg9300/data'
User = postgres
ExecStart = /usr/local/pgsql16/server/bin/pg_autoctl run
Restart = always
StartLimitBurst = 0
ExecReload = /usr/local/pgsql16/server/bin/pg_autoctl reload
WantedBy = multi-user.target
root@ubuntu13:/usr/local/pg_install_package# pg_autoctl -q show systemd --pgdata "/usr/local/pgsql16/pg9300/data" | tee /etc/systemd/system/pgautofailover.service
Description = pg_auto_failover
WorkingDirectory = /home/postgres
Environment = 'PGDATA=/usr/local/pgsql16/pg9300/data'
User = postgres
ExecStart = /usr/local/pgsql16/server/bin/pg_autoctl run
Restart = always
StartLimitBurst = 0
ExecReload = /usr/local/pgsql16/server/bin/pg_autoctl reload
WantedBy = multi-user.target
root@ubuntu13:/usr/local/pg_install_package# systemctl daemon-reload
root@ubuntu13:/usr/local/pg_install_package# systemctl enable pgautofailover
root@ubuntu13:/usr/local/pg_install_package# systemctl start pgautofailover
root@ubuntu13:/usr/local/pg_install_package#
root@ubuntu13:/usr/local/pg_install_package# systemctl status pgautofailover
● pgautofailover.service - pg_auto_failover
Loaded: loaded (/etc/systemd/system/pgautofailover.service; enabled; vendor preset: enabled)
Active: active (running) since Thu 2025-10-09 05:48:26 UTC; 5s ago
Main PID: 12381 (pg_autoctl)
Tasks: 9 (limit: 4550)
Memory: 42.0M
CGroup: /system.slice/pgautofailover.service
├─12381 /usr/local/pgsql16/server/bin/pg_autoctl run
├─12391 pg_autoctl: start/stop postgres
├─12392 pg_autoctl: node active
├─12402 /usr/local/pgsql16/server/bin/postgres -D /usr/local/pgsql16/pg9300/data -p 9300 -h *
├─12403 postgres: logger
├─12404 postgres: checkpointer
├─12405 postgres: background writer
├─12406 postgres: startup recovering 000000010000000000000003
└─12407 postgres: walreceiver streaming 0/3000110
Oct 09 05:48:27 ubuntu13 pg_autoctl: 05:48:27 12391 INFOPostgres is now serving PGDATA "/usr/local/pgsql16/pg9300/data" on port 9300 with pid 12402
Oct 09 05:48:27 ubuntu13 pg_autoctl: 05:48:27 12392 WARNPostgreSQL was not running, restarted with pid 12402
Oct 09 05:48:28 ubuntu13 pg_autoctl: 05:48:28 12392 INFOUpdated the keeper's state from the local PostgreSQL instance, which is running
Oct 09 05:48:28 ubuntu13 pg_autoctl: 05:48:28 12392 INFOpg_autoctl managed to ensure current state "catchingup": PostgreSQL is running
Oct 09 05:48:29 ubuntu13 pg_autoctl: 05:48:29 12392 INFOMonitor assigned new state "secondary"
Oct 09 05:48:29 ubuntu13 pg_autoctl: 05:48:29 12392 INFOFSM transition from "catchingup" to "secondary": Convinced the monitor that I'm up and running, and eligible for promotion again
Oct 09 05:48:29 ubuntu13 pg_autoctl: 05:48:29 12392 INFOReached timeline 1, same as upstream node 52 "ubuntu12" (ubuntu12:9300)
Oct 09 05:48:29 ubuntu13 pg_autoctl: 05:48:29 12392 INFOCreating replication slot "pgautofailover_standby_52"
Oct 09 05:48:29 ubuntu13 pg_autoctl: 05:48:29 12392 INFOTransition complete: current state is now "secondary"
Oct 09 05:48:29 ubuntu13 pg_autoctl: 05:48:29 12392 INFONew state for node 52 "ubuntu12" (ubuntu12:9300): primary ➜ primary
root@ubuntu13:/usr/local/pg_install_package# 5.2 monitor 节点查看已注册的从节点
再次回到monitor节点查看，可看到ubuntu11作为monitor节点，ubuntu12作为主节点，ubuntu13作为从节点
root@ubuntu11:~#
root@ubuntu11:~# pg_autoctl show uri;
Type | Name | Connection String
-------------+---------+-------------------------------
monitor | monitor | postgres://autoctl_node@ubuntu11:9300/pg_auto_failover?sslmode=require
formation | default | postgres://ubuntu12:9300,ubuntu13:9300/postgres?target_session_attrs=read-write&sslmode=require
root@ubuntu11:~#
root@ubuntu11:~#
root@ubuntu11:~# pg_autoctl show state
Name |Node | Host:Port | TLI: LSN | Connection | Reported State | Assigned State
---------+-------+---------------+----------------+--------------+---------------------+--------------------
ubuntu12 | 52 | ubuntu12:9300 | 1: 0/3000148 | read-write | primary | primary
ubuntu13 | 60 | ubuntu13:9300 | 1: 0/3000148 | read-only | secondary | secondary
root@ubuntu11:~#
root@ubuntu11:~#
6，pg_auto_failover外部访问配置
1，修改postgres用户密码
登录主节点修改postgres用户密码
ALTER USER postgres WITH PASSWORD 'a-strong-password';2，修改hba.conf
1，修改从节点ubuntu13的hba.conf，添加一下访问规则
hostssl postgres all 192.168.0.0/16 md5
2，重启主节点ubuntu12，此时故障转移，ubuntu13从节点提升为主节点，同时ubuntu13作为新的主节点，配置规则会覆盖从节点ubuntu12
pg_auto_failover的hba.conf覆盖规则是“新的主节点覆盖旧的主节点”，这一点有点绕，有兴趣的自己测试验证
然后从客户端连接至pg_auto_failover集群的主节点，查看复制状态，其实跟手动搭建的流复制就一样了，只不过是pg_auto_failover把整个postgresql集群的搭建过程给屏蔽掉了
SELECT * FROM pg_replication_slots;
slot_name |plugin|slot_type|datoid|database|temporary|active|active_pid|xmin|catalog_xmin|restart_lsn|confirmed_flush_lsn|wal_status|safe_wal_size|two_phase|conflicting|
-------------------------+------+---------+------+--------+---------+------+----------+----+------------+-----------+-------------------+----------+-------------+---------+-----------+
pgautofailover_standby_60| |physical | | |false |true| 11783|747 | |0/5020868| |reserved| |false | |
select * from pg_stat_replication;
pid|usesysid|usename |application_name |client_addr |client_hostname|client_port|backend_start |backend_xmin|state |sent_lsn |write_lsn|flush_lsn|replay_lsn|write_lag |flush_lag |replay_lag |sync_priority|sync_state|reply_time |
-----+--------+-------------------------+-------------------------+---------------+---------------+-----------+-----------------------------+------------+---------+---------+---------+---------+----------+---------------+---------------+---------------+-------------+----------+-----------------------------+
11783| 16416|pgautofailover_replicator|pgautofailover_standby_60|192.168.152.123|ubuntu13 | 60426|2025-10-09 13:23:00.095 +0800| |streaming|0/5020868|0/5020868|0/5020868|0/5020868 |00:00:00.001064|00:00:00.001766|00:00:00.001773| 1|quorum |2025-10-09 13:51:42.416 +0800|可以看到，pg_auto_failover在一主一从的模式下，是同步复制
select * from pg_settings where name like '%synchronous_commit%';
name |setting|unit|category |short_desc |extra_desc|context|vartype|source |min_val|max_val|enumvals |boot_val|reset_val|sourcefile |sourceline|pending_restart|
------------------+-------+----+--------------------------+-----------------------------------------------------+----------+-------+-------+------------------+-------+-------+----------------------------------------+--------+---------+------------------------------------------------------------+----------+---------------+
synchronous_commit|on | |Write-Ahead Log / Settings|Sets the current transaction''s synchronization level.| |user |enum |configuration file| | |{local,remote_write,remote_apply,on,off}|on |on |/usr/local/pgsql16/pg9300/data/postgresql-auto-failover.conf| 12|false |
select * from pg_settings where name like '%synchronous_standby_names%' ;
name |setting |unit|category |short_desc |extra_desc|context|vartype|source |min_val|max_val|enumvals|boot_val|reset_val |sourcefile |sourceline|pending_restart|
-------------------------+---------------------------------+----+----------------------------+-------------------------------------------------------------------------------+----------+-------+-------+------------------+-------+-------+--------+--------+---------------------------------+---------------------------------------------------+----------+---------------+
synchronous_standby_names|ANY 1 (pgautofailover_standby_60)| |Replication / Primary Server|Number of synchronous standbys and list of names of potential synchronous ones.| |sighup |string |configuration file| | |NULL | |ANY 1 (pgautofailover_standby_60)|/usr/local/pgsql16/pg9300/data/postgresql.auto.conf| 4|false |
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