PolarDB for PG是否有单点故障（搭建分布式的polardb）

没有。通过onekey.sh all或者pgxc_ctl -c $HOME/polardb/polardb_paxos.conf prepare standalone命令部署得到的polardb默认是有三节点部署在同一台物理机器上的。通过将 polardb_paxos.conf配置文件中localhost改为对应的机器ip，就可以避免单点故障。（注意三台机器的ssh需要被打通） 更改文件示例： datanodeMasterServers=(localhost) # none means this master is not available. datanodeSlaveServers=(localhost) # value none means this slave is not available datanodeLearnerServers=(localhost) # value none means this learner is not available ——> datanodeMasterServers=(Server1 IP) # none means this master is not available. datanodeSlaveServers=(Server2 IP) # value none means this slave is not available datanodeLearnerServers=(Server3 IP) # value none means this learner is not available