PostgreSQL ++patroni+etcd+haproxy+keepalived安装部署
三台虚机作为演示环境，软件版本规划如下:
Postgresql： 12.2
patroni： 2.1.4
etcd : 3.3.11
HAProxy ：1.5.18
Keepalived ：1.3.5
部署规划如下:
| 主机 |
IP |
组件 |
备注 |
| node1 |
192.168.30.152 |
PostgreSQL、Patroni、Etcd，haproxy、keepalived |
主节点 |
| node2 |
192.168.30.80 |
PostgreSQL、Patroni、Etcd、haproxy、keepalived |
备节点1 |
| node3 |
192.168.30.208 |
PostgreSQL、Patroni、Etcd、haproxy、keepalived |
备节点2 |
安装postgresql集群（略）
postgresql主库状态
[postgres@node1 bin]$ pg_controldata |grep cluster
Database cluster state: in production
node2节点状态
[postgres@node2 ~]$ pg_controldata |grep cluster
Database cluster state: in archive recovery
node3节点状态
[postgres@node3 ~]$ pg_controldata |grep cluster
Database cluster state: in archive recovery
集群状态
postgres=# select * from pg_stat_replication ;
pid | usesysid | usename | application_name | client_addr | client_hostname | client_port | backend_start | ba
ckend_xmin | state | sent_lsn | write_lsn | flush_lsn | replay_lsn | write_lag | flush_lag | replay_lag | sync_priority | sync_
state | reply_time
------+----------+----------+------------------+----------------+-----------------+-------------+-------------------------------+---
-----------+-----------+-----------+-----------+-----------+------------+-----------+-----------+------------+---------------+------
------+-------------------------------
3955 | 16384 | repluser | node2 | 192.168.30.80 | | 58612 | 2022-07-19 10:03:30.797054+08 |
| streaming | 0/B0014F0 | 0/B0014F0 | 0/B0014F0 | 0/B0014F0 | | | | 1 | sync
| 2022-07-19 10:03:05.772113+08
3979 | 16384 | repluser | node3 | 192.168.30.208 | | 38314 | 2022-07-19 10:03:35.850845+08 |
| streaming | 0/B0014F0 | 0/B0014F0 | 0/B0014F0 | 0/B0014F0 | | | | 0 | async
| 2022-07-19 10:04:48.118754+08安装 etcd
三节点安装 yum install etcd
node1节点配置
cat /etc/etcd/etcd.conf
ETCD_DATA_DIR="/var/lib/etcd/node1.etcd"
ETCD_LISTEN_PEER_URLS="http://192.168.30.152:2380"
ETCD_LISTEN_CLIENT_URLS="http://192.168.30.152:2379,http://127.0.0.1:2379"
ETCD_NAME="node1"
ETCD_INITIAL_ADVERTISE_PEER_URLS="http://192.168.30.152:2380"
ETCD_ADVERTISE_CLIENT_URLS="http://192.168.30.152:2379"
ETCD_INITIAL_CLUSTER="node1=http://192.168.30.152:2380,node2=http://192.168.30.80:2380,node3=http://192.168.30.208:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
node2节点配置
ETCD_DATA_DIR="/var/lib/etcd/node2.etcd"
ETCD_LISTEN_PEER_URLS="http://192.168.30.80:2380"
ETCD_LISTEN_CLIENT_URLS="http://192.168.30.80:2379,http://127.0.0.1:2379"
ETCD_NAME="node2"
ETCD_INITIAL_ADVERTISE_PEER_URLS="http://192.168.30.80:2380"
ETCD_ADVERTISE_CLIENT_URLS="http://192.168.30.80:2379"
ETCD_INITIAL_CLUSTER="node1=http://192.168.30.152:2380,node2=http://192.168.30.80:2380,node3=http://192.168.30.208:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
node3节点配置
ETCD_DATA_DIR="/var/lib/etcd/node3.etcd"
ETCD_LISTEN_PEER_URLS="http://192.168.30.208:2380"
ETCD_LISTEN_CLIENT_URLS="http://192.168.30.208:2379,http://127.0.0.1:2379"
ETCD_NAME="node3"
ETCD_INITIAL_ADVERTISE_PEER_URLS="http://192.168.30.208:2380"
ETCD_ADVERTISE_CLIENT_URLS="http://192.168.30.208:2379"
ETCD_INITIAL_CLUSTER="node1=http://192.168.30.152:2380,node2=http://192.168.30.80:2380,node3=http://192.168.30.208:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
依次启动 node1、node2、node3 节点的 etcd
systemctl start etcd.service
systemctl status etcd.service
systemctl enable etcd.service
检查etcd状态
etcdctl member list
[postgres@node1 bin]$ etcdctl member list
8073957066143594: name=node3 peerURLs=http://192.168.30.208:2380 clientURLs=http://192.168.30.208:2379 isLeader=false
a4871b3047aa7fcc: name=node2 peerURLs=http://192.168.30.80:2380 clientURLs=http://192.168.30.80:2379 isLeader=true
e06b6b4dbcc68272: name=node1 peerURLs=http://192.168.30.152:2380 clientURLs=http://192.168.30.152:2379 isLeader=false
安装 patroni
yum install -y gcc epel-release
yum install -y python-pip python-psycopg2 python-devel
wget https://bootstrap.pypa.io/pip/3.5/get-pip.py
python get-pip.py
pip install --upgrade pip
pip install --upgrade setuptools
pip install psycopg2-binary
pip install six
pip install patroni[etcd]
node1节点配置
[root@node1 etcd]# cat /usr/patroni/patroni_postgresql.yml
scope: postgres_cluster
namespace: /service/
name: node1
restapi:
listen: 192.168.30.152:8008
connect_address: 192.168.30.152:8008
etcd:
host: 192.168.30.152:2379
bootstrap:
# and all other cluster members will use it as a `global configuration`
dcs:
ttl: 30
loop_wait: 10
retry_timeout: 10
maximum_lag_on_failover: 1048576
master_start_timeout: 300
synchronous_mode: on
postgresql:
use_pg_rewind: true
use_slots: true
parameters:
listen_addresses: "0.0.0.0"
port: 5432
wal_level: "replica"
hot_standby: "on"
wal_keep_segments: 1000
max_wal_senders: 10
max_replication_slots: 10
wal_log_hints: "on"
# some desired options for 'initdb'
initdb: # Note: It needs to be a list (some options need values, others are switches)
- encoding: UTF8
- data-checksums
pg_hba: # Add following lines to pg_hba.conf after running 'initdb'
- host replication repluser 192.168.30.152/32 md5
- host replication repluser 192.168.30.80/32 md5
- host replication repluser 192.168.30.208/32 md5
- host all all 0.0.0.0/0 md5
postgresql:
listen: 0.0.0.0:5432
connect_address: 192.168.30.152:5432
data_dir: /data/postgres
bin_dir: /home/postgres/postgres/bin
authentication:
replication:
username: repluser
password: repluser
superuser:
username: postgres
password: postgres
rewind:
username: postgres
password: postgres
tags:
nofailover: false
noloadbalance: false
clonefrom: false
nosync: false
node2节点配置
[root@node2 ~]# cat /usr/patroni/patroni_postgresql.yml
scope: postgres_cluster
namespace: /service/
name: node2
restapi:
listen: 192.168.30.80:8008
connect_address: 192.168.30.80:8008
etcd:
host: 192.168.30.80:2379
bootstrap:
# and all other cluster members will use it as a `global configuration`
dcs:
ttl: 30
loop_wait: 10
retry_timeout: 10
maximum_lag_on_failover: 1048576
master_start_timeout: 300
synchronous_mode: on
postgresql:
use_pg_rewind: true
use_slots: true
parameters:
listen_addresses: "0.0.0.0"
port: 5432
wal_level: "replica"
hot_standby: "on"
wal_keep_segments: 1000
max_wal_senders: 10
max_replication_slots: 10
wal_log_hints: "on"
# some desired options for 'initdb'
initdb: # Note: It needs to be a list (some options need values, others are switches)
- encoding: UTF8
- data-checksums
pg_hba: # Add following lines to pg_hba.conf after running 'initdb'
- host replication repluser 192.168.30.152/32 md5
- host replication repluser 192.168.30.80/32 md5
- host replication repluser 192.168.30.208/32 md5
- host all all 0.0.0.0/0 md5
postgresql:
listen: 0.0.0.0:5432
connect_address: 192.168.30.80:5432
data_dir: /data/postgres
bin_dir: /home/postgres/postgres/bin
authentication:
replication:
username: repluser
password: repluser
superuser:
username: postgres
password: postgres
rewind:
username: postgres
password: postgres
tags:
nofailover: false
noloadbalance: false
clonefrom: false
nosync: false
node3节点配置
[root@node3 patroni]# cat /usr/patroni/patroni_postgresql.yml
scope: postgres_cluster
namespace: /service/
name: node3
restapi:
listen: 192.168.30.208:8008
connect_address: 192.168.30.208:8008
etcd:
host: 192.168.30.208:2379
bootstrap:
# and all other cluster members will use it as a `global configuration`
dcs:
ttl: 30
loop_wait: 10
retry_timeout: 10
maximum_lag_on_failover: 1048576
master_start_timeout: 300
synchronous_mode: on
postgresql:
use_pg_rewind: true
use_slots: true
parameters:
listen_addresses: "0.0.0.0"
port: 5432
wal_level: "replica"
hot_standby: "on"
wal_keep_segments: 1000
max_wal_senders: 10
max_replication_slots: 10
wal_log_hints: "on"
# some desired options for 'initdb'
initdb: # Note: It needs to be a list (some options need values, others are switches)
- encoding: UTF8
- data-checksums
pg_hba: # Add following lines to pg_hba.conf after running 'initdb'
- host replication repluser 192.168.30.152/32 md5
- host replication repluser 192.168.30.80/32 md5
- host replication repluser 192.168.30.208/32 md5
- host all all 0.0.0.0/0 md5
postgresql:
listen: 0.0.0.0:5432
connect_address: 192.168.30.208:5432
data_dir: /data/postgres
bin_dir: /home/postgres/postgres/bin
authentication:
replication:
username: repluser
password: repluser
superuser:
username: postgres
password: postgres
rewind:
username: postgres
password: postgres
tags:
nofailover: false
noloadbalance: false
clonefrom: false
nosync: false
通过 patroni 来管理 postgresql
systemctl status patroni
systemctl start patroni
systemctl enable patroni
[postgres@node1 bin]$ systemctl status patroni
● patroni.service - patroni - a high-availability PostgreSQL
Loaded: loaded (/etc/systemd/system/patroni.service; enabled; vendor preset: disabled)
Active: active (running) since Mon 2022-07-18 13:54:40 CST; 20h ago
Docs: https://patroni.readthedocs.io/en/latest/index.html
Main PID: 4695 (patroni)
CGroup: /system.slice/patroni.service
├─3937 postgres: postgres_cluster: walwriter
├─3938 postgres: postgres_cluster: autovacuum launcher
├─3939 postgres: postgres_cluster: logical replication launcher
├─3955 postgres: postgres_cluster: walsender repluser 192.168.30.80(58612) streaming 0/B0014F0
├─3979 postgres: postgres_cluster: walsender repluser 192.168.30.208(38314) streaming 0/B0014F0
├─4695 /usr/bin/python /usr/bin/patroni /usr/patroni/patroni_postgresql.yml
├─4715 /home/postgres/postgres/bin/postgres -D /data/postgres --config-file=/data/postgres/postgresql.conf --listen_ad...
├─4717 postgres: postgres_cluster: logger
├─4719 postgres: postgres_cluster: checkpointer
├─4720 postgres: postgres_cluster: background writer
├─4721 postgres: postgres_cluster: stats collector
└─4727 postgres: postgres_cluster: postgres postgres 127.0.0.1(58014) idle
查看 patroni 集群状态
patronictl -c /usr/patroni/patroni_postgresql.yml list
[postgres@node1 bin]$ patronictl -c /usr/patroni/patroni_postgresql.yml list
+ Cluster: postgres_cluster (7120985716210081590) -+----+-----------+
| Member | Host | Role | State | TL | Lag in MB |
+--------+----------------+--------------+---------+----+-----------+
| node1 | 192.168.30.152 | Leader | running | 8 | |
| node2 | 192.168.30.80 | Sync Standby | running | 8 | 0.0 |
| node3 | 192.168.30.208 | Replica | running | 8 | 0.0 |
+--------+----------------+--------------+---------+----+-----------+
安装haproxy
yum install -y haproxy
[root@node1 etcd]# cat /etc/haproxy/haproxy.cfg
global
maxconn 100000
log 127.0.0.1 local0 info
log 127.0.0.1 local1 warning
chroot /var/lib/haproxy
# stats socket /run/haproxy/admin.sock mode 660 level admin expose-fd listeners
stats timeout 30s
user postgres
daemon
defaults
mode tcp
log global
retries 2
timeout queue 5s
timeout connect 5s
timeout client 60m
timeout server 60m
timeout check 15s
listen stats
mode http
bind *:7000
stats enable
stats uri /
listen master
bind 192.168.30.100:5000
maxconn 10000
option tcplog
option httpchk OPTIONS /master
http-check expect status 200
default-server inter 3s fastinter 1s fall 3 rise 4 on-marked-down shutdown-sessions
server node1 192.168.30.152:5432 check port 8008
server node2 192.168.30.80:5432 check port 8008
server node3 192.168.30.208:5432 check port 8008
listen replicas
bind 192.168.30.100:5001
maxconn 10000
option tcplog
option httpchk OPTIONS /replica
balance roundrobin
http-check expect status 200
default-server inter 3s fastinter 1s fall 3 rise 2 on-marked-down shutdown-sessions
server node1 192.168.30.152:5432 check port 8008
server node2 192.168.30.80:5432 check port 8008
server node3 192.168.30.208:5432 check port 8008
[root@node2 ~]# cat /etc/haproxy/haproxy.cfg
global
maxconn 100000
log 127.0.0.1 local0 info
log 127.0.0.1 local1 warning
chroot /var/lib/haproxy
# stats socket /run/haproxy/admin.sock mode 660 level admin expose-fd listeners
stats timeout 30s
user postgres
daemon
defaults
mode tcp
log global
retries 2
timeout queue 5s
timeout connect 5s
timeout client 60m
timeout server 60m
timeout check 15s
listen stats
mode http
bind *:7000
stats enable
stats uri /
listen master
bind 192.168.30.100:5000
maxconn 10000
option tcplog
option httpchk OPTIONS /master
http-check expect status 200
default-server inter 3s fastinter 1s fall 3 rise 4 on-marked-down shutdown-sessions
server node1 192.168.30.152:5432 check port 8008
server node2 192.168.30.80:5432 check port 8008
server node3 192.168.30.208:5432 check port 8008
listen replicas
bind 192.168.30.100:5001
maxconn 10000
option tcplog
option httpchk OPTIONS /replica
balance roundrobin
http-check expect status 200
default-server inter 3s fastinter 1s fall 3 rise 2 on-marked-down shutdown-sessions
server node1 192.168.30.152:5432 check port 8008
server node2 192.168.30.80:5432 check port 8008
server node3 192.168.30.208:5432 check port 8008
[root@node3 patroni]# cat /etc/haproxy/haproxy.cfg
global
maxconn 100000
log 127.0.0.1 local0 info
log 127.0.0.1 local1 warning
chroot /var/lib/haproxy
# stats socket /run/haproxy/admin.sock mode 660 level admin expose-fd listeners
stats timeout 30s
user postgres
daemon
defaults
mode tcp
log global
retries 2
timeout queue 5s
timeout connect 5s
timeout client 60m
timeout server 60m
timeout check 15s
listen stats
mode http
bind *:7000
stats enable
stats uri /
listen master
bind 192.168.30.100:5000
maxconn 10000
option tcplog
option httpchk OPTIONS /master
http-check expect status 200
default-server inter 3s fastinter 1s fall 3 rise 4 on-marked-down shutdown-sessions
server node1 192.168.30.152:5432 check port 8008
server node2 192.168.30.80:5432 check port 8008
server node3 192.168.30.208:5432 check port 8008
listen replicas
bind 192.168.30.100:5001
maxconn 10000
option tcplog
option httpchk OPTIONS /replica
balance roundrobin
http-check expect status 200
default-server inter 3s fastinter 1s fall 3 rise 2 on-marked-down shutdown-sessions
server node1 192.168.30.152:5432 check port 8008
server node2 192.168.30.80:5432 check port 8008
server node3 192.168.30.208:5432 check port 8008
启动haproxy
systemctl status haproxy
systemctl start haproxy
[root@node1 etcd]# systemctl status haproxy
● haproxy.service - HAProxy Load Balancer
Loaded: loaded (/usr/lib/systemd/system/haproxy.service; disabled; vendor preset: disabled)
Active: active (running) since Tue 2022-07-19 10:11:11 CST; 2s ago
Main PID: 5317 (haproxy-systemd)
CGroup: /system.slice/haproxy.service
├─5317 /usr/sbin/haproxy-systemd-wrapper -f /etc/haproxy/haproxy.cfg -p /run/haproxy.pid
├─5318 /usr/sbin/haproxy -f /etc/haproxy/haproxy.cfg -p /run/haproxy.pid -Ds
└─5319 /usr/sbin/haproxy -f /etc/haproxy/haproxy.cfg -p /run/haproxy.pid -Ds
Jul 19 10:11:11 node1 systemd[1]: Started HAProxy Load Balancer.
Jul 19 10:11:11 node1 haproxy-systemd-wrapper[5317]: haproxy-systemd-wrapper: executing /usr/sbin/haproxy -f /etc/haproxy/ha...d -Ds
Jul 19 10:11:11 node1 haproxy-systemd-wrapper[5317]: [WARNING] 199/101111 (5318) : config : frontend 'GLOBAL' has no 'bind' ...nded.
Hint: Some lines were ellipsized, use -l to show in full.
安装keepalived
yum install -y keepalived
[root@node1 etcd]# cat /etc/keepalived/keepalived.conf
global_defs {
router_id LVS_DEVEL
}
vrrp_script check_leader {
script "/usr/bin/curl -s http://127.0.0.1:8008/leader -v 2>&1|grep '200 OK' >/dev/null"
interval 2
weight 10
}
vrrp_script check_replica {
script "/usr/bin/curl -s http://127.0.0.1:8008/replica -v 2>&1|grep '200 OK' >/dev/null"
interval 2
weight 5
}
vrrp_script check_can_read {
script "/usr/bin/curl -s http://127.0.0.1:8008/read-only -v 2>&1|grep '200 OK' >/dev/null"
interval 2
weight 10
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 211
priority 100
advert_int 1
track_script {
check_can_read
check_replica
}
virtual_ipaddress {
192.168.30.100
}
}
[root@node2 ~]# cat /etc/keepalived/keepalived.conf
global_defs {
router_id LVS_DEVEL
}
vrrp_script check_leader {
script "/usr/bin/curl -s http://127.0.0.1:8008/leader -v 2>&1|grep '200 OK' >/dev/null"
interval 2
weight 10
}
vrrp_script check_replica {
script "/usr/bin/curl -s http://127.0.0.1:8008/replica -v 2>&1|grep '200 OK' >/dev/null"
interval 2
weight 5
}
vrrp_script check_can_read {
script "/usr/bin/curl -s http://127.0.0.1:8008/read-only -v 2>&1|grep '200 OK' >/dev/null"
interval 2
weight 10
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 211
priority 100
advert_int 1
track_script {
check_can_read
check_replica
}
virtual_ipaddress {
192.168.30.100
}
}
[root@node3 patroni]# cat /etc/keepalived/keepalived.conf
global_defs {
router_id LVS_DEVEL
}
vrrp_script check_leader {
script "/usr/bin/curl -s http://127.0.0.1:8008/leader -v 2>&1|grep '200 OK' >/dev/null"
interval 2
weight 10
}
vrrp_script check_replica {
script "/usr/bin/curl -s http://127.0.0.1:8008/replica -v 2>&1|grep '200 OK' >/dev/null"
interval 2
weight 5
}
vrrp_script check_can_read {
script "/usr/bin/curl -s http://127.0.0.1:8008/read-only -v 2>&1|grep '200 OK' >/dev/null"
interval 2
weight 10
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 211
priority 100
advert_int 1
track_script {
check_can_read
check_replica
}
virtual_ipaddress {
192.168.30.100
}
}
启动keepalived
systemctl start keepalived
systemctl status keepalived
[root@node1 etcd]# systemctl status keepalived
● keepalived.service - LVS and VRRP High Availability Monitor
Loaded: loaded (/usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)
Active: active (running) since Tue 2022-07-19 10:13:07 CST; 1s ago
Process: 5745 ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS (code=exited, status=0/SUCCESS)
Main PID: 5747 (keepalived)
CGroup: /system.slice/keepalived.service
├─5747 /usr/sbin/keepalived -D
├─5748 /usr/sbin/keepalived -D
└─5749 /usr/sbin/keepalived -D
Jul 19 10:13:07 node1 Keepalived_vrrp[5749]: Registering gratuitous ARP shared channel
Jul 19 10:13:07 node1 Keepalived_vrrp[5749]: Opening file '/etc/keepalived/keepalived.conf'.
Jul 19 10:13:07 node1 Keepalived_vrrp[5749]: WARNING - default user 'keepalived_script' for script execution does not exist...reate.
Jul 19 10:13:07 node1 Keepalived_vrrp[5749]: SECURITY VIOLATION - scripts are being executed but script_security not enabled.
Jul 19 10:13:07 node1 Keepalived_vrrp[5749]: VRRP_Instance(VI_1) removing protocol VIPs.
Jul 19 10:13:07 node1 Keepalived_vrrp[5749]: Using LinkWatch kernel netlink reflector...
Jul 19 10:13:07 node1 Keepalived_vrrp[5749]: VRRP_Instance(VI_1) Entering BACKUP STATE
Jul 19 10:13:07 node1 Keepalived_vrrp[5749]: VRRP sockpool: [ifindex(2), proto(112), unicast(0), fd(10,11)]
Jul 19 10:13:07 node1 Keepalived_vrrp[5749]: /usr/bin/curl -s http://127.0.0.1:8008/replica -v 2>&1|grep '200 OK' >/dev/nul...atus 1
Jul 19 10:13:07 node1 Keepalived_vrrp[5749]: /usr/bin/curl -s http://127.0.0.1:8008/read-only -v 2>&1|grep '200 OK' >/dev/n...atus 1
Hint: Some lines were ellipsized, use -l to show in full.
VIP绑定
node1节点VIP绑定eth0网卡设备
[root@node1 etcd]# ip a
1: lo: mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
link/ether a6:75:b8:69:57:9d brd ff:ff:ff:ff:ff:ff
inet 192.168.30.152/24 brd 192.168.30.255 scope global noprefixroute dynamic eth0
valid_lft 28322sec preferred_lft 28322sec
inet 192.168.30.100/32 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::b343:d202:c83f:6573/64 scope link tentative noprefixroute dadfailed
valid_lft forever preferred_lft forever
inet6 fe80::7aaf:69b6:7c81:9d35/64 scope link tentative noprefixroute dadfailed
valid_lft forever preferred_lft forever
inet6 fe80::2562:23d:6bee:d2ae/64 scope link tentative noprefixroute dadfailed
valid_lft forever preferred_lft forever
集群测试
通过VIP访问不同接口，实现读写分离和负载均衡
1、访问5000端口，连接读写主节点
[postgres@node2 ~]$ psql -h 192.168.30.100 -p 5000
Password for user postgres:
psql (12.2)
Type "help" for help.
postgres=# select inet_server_addr(),pg_is_in_recovery();
inet_server_addr | pg_is_in_recovery
------------------+-------------------
192.168.30.152 | f
2、访问5001端口，连接读节点，实现负载均衡
[postgres@node2 ~]$ psql -h 192.168.30.100 -p 5001
Password for user postgres:
psql (12.2)
Type "help" for help.
postgres=# select inet_server_addr(),pg_is_in_recovery();
inet_server_addr | pg_is_in_recovery
------------------+-------------------
192.168.30.80 | t
手动切换Leader
patronictl -c /usr/patroni/patroni_postgresql.yml switchover
[root@node2 ~]# patronictl -c /usr/patroni/patroni_postgresql.yml switchover
Master [node2]:
Candidate ['node1', 'node3'] []: node1
When should the switchover take place (e.g. 2022-07-19T11:01 ) [now]: now
Current cluster topology
+ Cluster: postgres_cluster (7120985716210081590) -+----+-----------+
| Member | Host | Role | State | TL | Lag in MB |
+--------+----------------+--------------+---------+----+-----------+
| node1 | 192.168.30.152 | Sync Standby | running | 7 | 0.0 |
| node2 | 192.168.30.80 | Leader | running | 7 | |
| node3 | 192.168.30.208 | Replica | running | 7 | 0.0 |
+--------+----------------+--------------+---------+----+-----------+
Are you sure you want to switchover cluster postgres_cluster, demoting current master node2? [y/N]: y
2022-07-19 10:01:14.23857 Successfully switched over to "node1"
+ Cluster: postgres_cluster (7120985716210081590) -+-----------+
| Member | Host | Role | State | TL | Lag in MB |
+--------+----------------+---------+---------+----+-----------+
| node1 | 192.168.30.152 | Leader | running | 7 | |
| node2 | 192.168.30.80 | Replica | stopped | | unknown |
| node3 | 192.168.30.208 | Replica | running | 7 | 0.0 |
+--------+----------------+---------+---------+----+-----------+
[root@node2 ~]# patronictl -c /usr/patroni/patroni_postgresql.yml list
+ Cluster: postgres_cluster (7120985716210081590) -+----+-----------+
| Member | Host | Role | State | TL | Lag in MB |
+--------+----------------+--------------+---------+----+-----------+
| node1 | 192.168.30.152 | Leader | running | 8 | |
| node2 | 192.168.30.80 | Sync Standby | running | 8 | 0.0 |
| node3 | 192.168.30.208 | Replica | running | 8 | 0.0 |
+--------+----------------+--------------+---------+----+-----------+