在Linux系统中搭建PostgreSQL集群,通常指的是设置一个高可用性的PostgreSQL集群,以确保数据库服务的连续性和数据的一致性。以下是使用Patroni和Pacemaker搭建PostgreSQL集群的基本步骤:
在所有服务器上安装必要的软件包:
sudo apt-get update
sudo apt-get install -y pacemaker pcs patroni postgresql
安装Corosync:
sudo apt-get install -y corosync
配置Corosync:
编辑/etc/corosync/corosync.conf文件,配置集群节点信息:
totem {
version: 2
cluster_name: pg_cluster
transport: udpu
}
nodelist {
node {
ring0_addr: server1_ip
nodeid: 1
}
node {
ring0_addr: server2_ip
nodeid: 2
}
node {
ring0_addr: server3_ip
nodeid: 3
}
}
quorum {
provider: corosync_votequorum
}
logging {
to_logfile: yes
logfile: /var/log/corosync/corosync.log
to_syslog: yes
}
启动并启用Corosync服务:
sudo systemctl start corosync
sudo systemctl enable corosync
加入集群: 在每台服务器上运行以下命令加入集群:
sudo pcs cluster join --name server1_ip
配置Pacemaker:
编辑/etc/pacemaker/cib.xml文件,定义资源和服务:
<cib xmlns:schemaLocation="urn:org:corosync:cib:1.0" version="150000">
<fence_daemon enable="true" />
<cluster_name>pg_cluster</cluster_name>
<primitive id="ocf:heartbeat:pgsql" class="ocf" type="pgsql">
<operations>
<op id="start" name="start" interval="0s" timeout="60s" />
<op id="stop" name="stop" interval="0s" timeout="60s" />
<op id="monitor" name="monitor" interval="30s" timeout="60s" />
</operations>
<instance_attributes id="pgsql-instance-attributes">
<nvpair id="pgsql-data" name="data" value="/var/lib/postgresql/12/main" />
<nvpair id="pgsql-log" name="log" value="/var/log/postgresql/" />
<nvpair id="pgsql-conf" name="conf" value="/etc/postgresql/12/main/postgresql.conf" />
</instance_attributes>
<resources>
<primitive id="pgsql" class="ocf" type="pgsql">
<instances>
<instance id="pgsql-instance" />
</instances>
</primitive>
</resources>
</primitive>
</cib>
启动Pacemaker服务:
sudo systemctl start pacemaker
sudo systemctl enable pacemaker
安装Patroni: 在每台服务器上安装Patroni:
sudo apt-get install -y patroni
配置Patroni:
编辑/etc/patroni.yml文件,配置Patroni实例:
scope: postgresql
name: server1_ip
namespace: /db
restapi:
listen: 0.0.0.0:8008
connect_address: server1_ip
etcd:
host: etcd_server_ip
port: 2379
bootstrap:
dcs:
ttl: 30
loop_wait: 10
retry_timeout: 10
maximum_lag_on_failover: 1048576
postgresql:
use_pg_rewind: true
use_slots: true
parameters:
wal_level: replica
max_connections: 100
hot_standby: on
postgresql:
listen: 0.0.0.0:5432
connect_address: 127.0.0.1
data_dir: /var/lib/postgresql/12/main
pg_hba:
- host replication replicator 0.0.0.0/0 md5
authentication:
replication:
username: replicator
password: replicator_password
启动Patroni:
sudo systemctl start patroni
sudo systemctl enable patroni
使用以下命令检查集群状态:
sudo pcs status
sudo patronesi status
通过以上步骤,你应该能够在Linux系统上成功搭建一个PostgreSQL集群。请根据实际情况调整配置文件中的参数。