PostgreSQL的 Slony-I 数据同步

原文--http://www.tuicool.com/articles/mMvARf

先谈谈slony的局限性：

1. DDL动作是不会被复制到；

2. 如果想使用slony来同步数据，表必须是带有主键的

内容大家看原文；个人感觉总结的很好！

下面是为slony维护；定制的脚本

包括了服务启动/关闭；以及slony set删除/安装。

#!/bin/sh

SLONIK=/opt/pgsql/bin/slonik
SLON=/opt/pgsql/bin/slon
CLUSTER_NAME=lottu_cluster
MASTERDBNAME=masterdb
SLAVEDBNAME=slavedb
MASTERHOST=192.168.8.121
SLAVEHOST=192.168.8.120
REPLICATIONUSER=postgres
PASSWORD=li0924

uninstall()
{
    $SLONIK << _EOF_
        cluster name = $CLUSTER_NAME;

        node  admin conninfo = 'dbname=$MASTERDBNAME  host=$MASTERHOST user=$REPLICATIONUSER password=$PASSWORD';
        node  admin conninfo = 'dbname=$SLAVEDBNAME  host=$SLAVEHOST user=$REPLICATIONUSER password=$PASSWORD';

        uninstall node (id = );
        uninstall node (id = );
_EOF_
}

install()
{
    $SLONIK << _EOF_
    #--
    # define the namespace the replication system
    # uses in our example it is slony_example
    #--
    cluster name = $CLUSTERNAME;

    #--
    # admin conninfo's are used by slonik to connect to
    # the nodes one for eachnode on each side of the cluster,
    # the syntax is that of PQconnectdb in
    # the C-API
    # --

    node  admin conninfo = 'dbname=$MASTERDBNAME  host=$MASTERHOST user=$REPLICATIONUSER password=$PASSWORD';
    node  admin conninfo = 'dbname=$SLAVEDBNAME  host=$SLAVEHOST user=$REPLICATIONUSER password=$PASSWORD';

    #--
    # init the first node.  Its id MUST be 1.  This creates
    # the schema _$CLUSTERNAME containing all replication
    # system specific database objects.
    #--

    init cluster ( id=, comment = 'Master Node');

    #--
    # Slony-I organizes tables into sets.  The smallest unit
    # a node can subscribe is a set. The master or origin of
    # the set is node 1.
    #--
    create set (id=, origin=, comment='All lottu tables');
    set add table (set id=, origin=, id=,
                   fully qualified name = 'public.lottu',
                   comment='lottu table');

    # set add sequence (set id=1, origin = 1, id = 1,
    #               fully qualified name = 'public.t1_id_seq',
    #               comment = 't1 id sequence');

    #--
    # Create the second node (the slave) tell the 2 nodes how
    # to connect to each other and how they should listen for events.
    #--

    store node (id=, comment = );
    store path (server = , client = , conninfo='dbname=$MASTERDBNAME host=$MASTERHOST user=$REPLICATIONUSER password=$PASSWORD');
    store path (server = , client = , conninfo='dbname=$SLAVEDBNAME  host=$SLAVEHOST user=$REPLICATIONUSER password=$PASSWORD');
_EOF_
}

start()
{
    $SLON $CLUSTER_NAME "dbname=$MASTERDBNAME host=$MASTERHOST user=$REPLICATIONUSER password=$PASSWORD" >> /home/postgresql/master.log &
  #  $SLON $CLUSTER_NAME "$SLAVE" >> /home/postgresql/slave.log &
}

stop()
{
    # killall slon
      `ps axu|grep 'dbname=masterdb' |grep -v grep|awk '{print $2}'`
}

case $ in
    'install')
        install
        ;;
    'uninstall')
        uninstall
        ;;
    'start')
        start
        ;;
    'stop')
        stop
        ;;
    *)
        echo "usage: $0 {install|uninstall|start|stop} "
        ;;
esac