集群架构：
h236：master
h237:standby sync
h238:standby sync
h239:stadnby async
h240:standby async
h241:standby async
pool.conf
failover_command = '/etc/kingbasecluster/failover_stream.sh %H %P %d'
failover_stream.sh
#!/bin/sh
h238=172.19.33.238
h239=172.19.33.239
h240=172.19.33.240
h241=172.19.33.241
h236=172.19.33.236
h237=172.19.33.237
trigger_command="pg_ctl promote -D /data/pgdata"
fix_rec="sed -i 's/172.19.33.236./172.19.33.237/' /data/pgdata/recovery.conf;
pg_ctl -D /data/pgdata/ stop -m fast;pg_ctl -D /data/pgdata/ start"
#primary down
#236(node 0) , 237(node1)
if [$2 -eq $3 ];then
#node 236 down
if [ $2 -eq 0 ];then
/usr/bin/ssh -T $h237 $trigger_command
fi
#node 237 down #236手动修复称为standby之后
if [ $2 -eq 1 ];then
$fix_rec="sed -i 's/172.19.33.237./172.19.33.236/' /data/pgdata/recovery.conf;
pg_ctl -D /data/pgdata/ stop -m fast;pg_ctl -D /data/pgdata/ start"
/usr/bin/ssh -T $h236 $trigger_command
fi
#238-241 follow new primary
/usr/bin/ssh -T $h238 $fix_rec &
/usr/bin/ssh -T $h239 $fix_rec &
/usr/bin/ssh -T $h240 $fix_rec &
/usr/bin/ssh -T $h241 $fix_rec &
#do nothing for other standby down
fi
exit 0;
==============================================================================
failover命令中的参数使用描述
- failover_command
-
This parameter specifies a command to run when a node is detached. pgpool-II replaces the following special characters with backend specific information.
Special character Description %d Backend ID of a detached node. %h Hostname of a detached node. %p Port number of a detached node. %D Database cluster directory of a detached node. %M Old master node ID. %m New master node ID. %H Hostname of the new master node. %P Old primary node ID. %% '%' character You need to reload pgpool.conf if you change failover_command.
When a failover is performed, pgpool kills all its child processes, which will in turn terminate all active sessions to pgpool. Then pgpool invokes the failover_command and waits for its completion. After this, pgpool starts new child processes and is ready again to accept connections from clients.
- failback_command
-
This parameter specifies a command to run when a node is attached. pgpool-II replaces special the following characters with backend specific information.
Special character Description %d Backend ID of an attached node. %h Hostname of an attached node. %p Port number of an attached node. %D Database cluster path of an attached node. %M Old master node %m New master node %H Hostname of the new master node. %P Old primary node ID. %% '%' character You need to reload pgpool.conf if you change failback_command.