Slony-I基础篇

一、环境

通过VirtualBox创建两台虚拟机进行实验。

节点服务器     2台

    服务器1      操作系统      CentOS release 6.7 (Final)

                    主机名         ha1

                    角色            主节点

                    IP地址         192.168.100.151

                    数据库          postgresql-9.4.5

                    slony           slony1-2.2.4

    服务器2      操作系统      CentOS release 6.7 (Final)

                    主机名         ha2

                    角色            备节点

                    IP地址         192.168.100.152

                    数据库          postgresql-9.4.5

                    slony          slony1-2.2.4

二、操作系统

两个节点均需执行以下配置。

1、/etc/hosts

root用户编辑/etc/hosts文件，修改内容如下：

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4 

::1         localhost localhost.localdomain localhost6 localhost6.localdomain6 

192.168.100.151 ha1 

192.168.100.152 ha2 

2、防火墙

        root用户编辑/etc/sysconfig/iptables防火墙配置文件，开启PostgreSQL端口5432的远程访问，最终文件内容如下：

# Generated by iptables-save v1.4.7 on Tue Dec 29 10:45:17 2015 

*filter 

:INPUT ACCEPT [0:0] 

:FORWARD ACCEPT [0:0] 

:OUTPUT ACCEPT [26:2536] 

-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT  

-A INPUT -p icmp -j ACCEPT  

-A INPUT -i lo -j ACCEPT  

-A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT  

-A INPUT -p tcp -m state --state NEW -m tcp --dport 5432 -j ACCEPT  

-A INPUT -j REJECT --reject-with icmp-host-prohibited  

-A FORWARD -j REJECT --reject-with icmp-host-prohibited  

COMMIT 

# Completed on Tue Dec 29 10:45:17 2015 

        注意事项：

        新规则的位置必须在-A INPUT -j REJECT --reject-with icmp-host-prohibited、-A FORWARD -j REJECT --reject-with icmp-host-prohibited这两个规则之上，否则不会生效。

修改完成之后，重启iptables服务。

3、用户 及目录

root用户创建相应的操作系统用户、数据库目录及slony目录，并赋权。

[root@ha1 ~]# groupadd postgres 

[root@ha1 ~]# useradd –g postgres postgres 

[root@ha1 ~]# passwd postgres 

[root@ha1 ~]# mkdir –p /usr/local/pg945/data 

[root@ha1 ~]# mkdir –p /usr/local/slony/log 

[root@ha1 ~]# mkdir –p /usr/local/slony/archive 

[root@ha1 ~]# chown –R postgres:postgres /usr/local/pg945 

[root@ha1 ~]# chown –R postgres:postgres /usr/local/slony 

        配置postgres用户的环境变量，如下：

export PGBASE=/usr/local/pg945 

export PGDATA=$PGBASE/data 

export PGUSER=postgres 

export PGPORT=5432 

export PATH=$PATH:$HOME/bin:$PGBASE/bin:/usr/local/slony/bin 

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$PGBASE/lib 

三、数据库

两个节点均需执行以下配置。

1、安装

将下载的PostgreSQL数据库源码包放在/home/postgres目录下， postgres用户进行解压、安装。

安装目录为/usr/local/pg945，具体过程略。

安装完成之后，配置数据库允许远程访问，具体配置略。

2、数据准备

进入数据库，创建测试对象，操作如下：

[postgres@ha1 ~]$ psql  

psql (9.4.5) 

Type "help" for help. 

postgres=# create user slony superuser password 123456; 

postgres=# create database slony owner slony; 

postgres=# \c slony slony 

slony=# create schema slony authorization slony; 

slony=# create table tb1 (id int primary key,name varchar); 

四、slony

1、安装

两个节点均需执行编译安装。

将下载的Slony源码包放在/home/postgres目录下，postgres进行解压、安装。configure操作为：

[postgres@ha1 ~]$ ./configure --prefix=/usr/local/slony --with-perltools --with-pgconfigdir=/usr/local/pg945/bin 

        具体过程略。

2、slon进程配置

两个节点均需创建配置文件。

在/usr/local/slony/etc目录下创建配置文件slon.conf，最基本、主要的两个参数为：

cluster_name='slony' 

conn_info='host=localhost port=5432 user=slony' 

        具体文件内容参考附件。

3、slonik配置

        此处依照slony中添加资源的顺序进行说明，最终的完整脚本可参照附件。

        只需要在主节点执行脚本即可。

1）cluster

        可以理解为是一个数据库，其下存放了集群运行过程中所需要的配置信息，如节点、监听、数据库对象等。

结合手册，通过反复测试可以看出：

a) 一套slony集群只能有一个cluster，由cluster name定义

b) init cluster时需要先指定一个admin conninfo

c) admin conninfo所定义的节点即为主节点

d) 只需要定义主节点的conninfo即可，可不定义备节点

slonik定义如下：

cluster_name=slony 

master_conninfo="host=ha1 dbname=slony user=slony" 

slave_conninfo="host=ha2 dbname=slony user=slony" 

slonik <<EOF 

cluster name = $cluster_name; 

node 1 admin conninfo = '$master_conninfo'; 

init cluster (id=1, comment = 'Master Node'); 

EOF 

2）node

通过store node命令，定义一个node，然后将其保存至cluster的配置中（_$cluster_name.sl_node表）。

在这个过程中会新节点上创建一个_$cluster_name，这也是为什么上文中说的在init cluster时只需要主节点的conninfo信息，不需要备节点的信息。

由于从1.2.11版本开始加入了log shipping，所以不再需要配置spoolnode参数。

slonik脚本如下：

slonik <<EOF 

cluster name = $cluster_name; 

node 1 admin conninfo = '$master_conninfo'; 

node 2 admin conninfo = '$slave_conninfo'; 

store node (id = 2,comment = 'slave node',event node = 1); 

EOF 

通过反复测试得出：

a) store node中需要定义event node

b) event node得是已经存在的node

c) 在store node之前需要定义admin conninfo

d) 由于event node指定的是1，故还还需要指定node 1的admin conninfo

3）path

      通信路径（path）存储在_$cluster_name.sl_path中，在完成node定义之后，并不会在cluster中存储该node的链接信息，需要再通过store path命令来完成存储。

      通过store path命令向cluster中写入node的访问方式。类似于store node，需要在store node之前写入相关node的admin conninfo。

       slonik定义如下：

slonik <<EOF 

cluster name = $cluster_name; 

node 1 admin conninfo = '$master_conninfo'; 

node 2 admin conninfo = '$slave_conninfo'; 

store path (server = 1,client = 2,conninfo = '$master_conninfo'); 

store path (server = 2,client = 1,conninfo = '$slave_conninfo'); 

EOF

4）listen

通过store listen命令完成该操作。若sl_path中已存储了相应的listen信息，则会发生wait for event事件。

而且，store listen操作需要一条一条执行，不能同时执行多条。

slonik <<EOF 

cluster name = $cluster_name; 

node 1 admin conninfo = '$master_conninfo'; 

node 2 admin conninfo = '$slave_conninfo'; 

store listen (origin = 1, provider = 1, receiver = 2); 

EOF 

slonik <<EOF 

cluster name = $cluster_name; 

node 1 admin conninfo = '$master_conninfo'; 

node 2 admin conninfo = '$slave_conninfo'; 

store listen (origin = 2, provider = 2, receiver = 1); 

EOF 

5）set（origin）

        set是slony中的最小单元，存储要进行同步的数据库对象。

        set（origin发送端）信息存储在_$cluster_name.sl_set系统表中。

        slonik配置如下：

slonik <<EOF 

cluster name = $cluster_name; 

node 1 admin conninfo = '$master_conninfo'; 

node 2 admin conninfo = '$slave_conninfo'; 

create set (id = 1,origin = 1,comment = '1to2'); 

EOF 

6）table

        配置完发送set之后，需要向其中写入参与同步的表的信息。

        slonik配置如下：

slonik << EOF 

cluster name = $cluster_name; 

node 1 admin conninfo = 'host=$master_host dbname=$db_name user=$user_name'; 

node 2 admin conninfo = 'host=$slave_host dbname=$db_name user=$user_name'; 

set add table (set id = 1,origin = 1,fully qualified name='slony.tb1',comment='1to2'); 

EOF 

7）set（receive）

        set（receive接受端）信息存储在_$cluster_name.sl_subscribe系统表中。

        slonik配置如下：

slonik <<EOF 

cluster name = $cluster_name; 

node 1 admin conninfo = '$master_conninfo'; 

node 2 admin conninfo = '$slave_conninfo'; 

subscribe set (id = 1,provider = 1,receiver = 2,forward = no,omit copy = no); 

EOF

五、附件

1、数据库服务

#! /bin/sh

# chkconfig: 2345 64 36
# This is an example of a start/stop script
# if you have chkconfig, simply:
# chkconfig --add postgresql

prefix=/usr/local/pg945
PGDATA="/usr/local/pg945/data"
PGUSER=postgres
PGLOG="$PGDATA/pg_log/postgres-`date +%Y-%m-%d`.log"
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
DAEMON="$prefix/bin/postmaster"
PGCTL="$prefix/bin/pg_ctl"

set -e

test -x $DAEMON ||
{
	echo "$DAEMON not found"
	if [ "$1" = "stop" ]
	then exit 0
	else exit 5
	fi
}

case $1 in
  start)
	echo -n "Starting PostgreSQL: "
	test x"$OOM_SCORE_ADJ" != x && echo "$OOM_SCORE_ADJ" > /proc/self/oom_score_adj
	test x"$OOM_ADJ" != x && echo "$OOM_ADJ" > /proc/self/oom_adj
	su - $PGUSER -c "$DAEMON -D '$PGDATA' &" >>$PGLOG 2>&1
	echo "ok"
	;;
  stop)
	echo -n "Stopping PostgreSQL: "
	su - $PGUSER -c "$PGCTL stop -D '$PGDATA' -s -m fast"
	echo "ok"
	;;
  restart)
	echo -n "Restarting PostgreSQL: "
	su - $PGUSER -c "$PGCTL stop -D '$PGDATA' -s -m fast -w"
	test x"$OOM_SCORE_ADJ" != x && echo "$OOM_SCORE_ADJ" > /proc/self/oom_score_adj
	test x"$OOM_ADJ" != x && echo "$OOM_ADJ" > /proc/self/oom_adj
	su - $PGUSER -c "$DAEMON -D '$PGDATA' &" >>$PGLOG 2>&1
	echo "ok"
	;;
  reload)
        echo -n "Reload PostgreSQL: "
        su - $PGUSER -c "$PGCTL reload -D '$PGDATA' -s"
        echo "ok"
        ;;
  status)
	su - $PGUSER -c "$PGCTL status -D '$PGDATA'"
	;;
  *)
	# Print help
	echo "Usage: $0 {start|stop|restart|reload|status}" 1>&2
	exit 1
	;;
esac

exit 0

2、slony服务

#!/bin/sh

# chkconfig: - 98 02
# description: Starts and stops the Slon daemon that handles Slony-I replication.

if [ -r /etc/sysconfig/slony1 ]; then
    . /etc/sysconfig/slony1
fi

# Source function library.
INITD=/etc/rc.d/init.d
. $INITD/functions

# Get function listing for cross-distribution logic.
TYPESET=`typeset -f|grep "declare"`

# Get config.
. /etc/sysconfig/network

# For SELinux we need to use 'runuser' not 'su'
if [ -x /sbin/runuser ]
then
	SU=runuser
else
	SU=su
fi

# Check that networking is up.
# We need it for slon
[ "${NETWORKING}" = "no" ] && exit 0

# Find the name of the script
NAME=`basename $0`
if [ ${NAME:0:1} = "S" -o ${NAME:0:1} = "K" ]
then
	NAME=${NAME:3}
fi

# Set defaults for configuration variables
SLONENGINE=/usr/local/slony/bin
SLONDAEMON=$SLONENGINE/slon
SLONCONF=$SLONENGINE/etc/slon.conf
SLONPID=/usr/local/slony/slon.pid
SLONLOG=/usr/local/slony/log/slony-`date +%Y-%m-%d`.log
test -x $SLONDAEMON || exit 5
script_result=0

cluster_name=slony
conn_info="\"host=localhost port=5432 user=slony\""

start(){
	SLON_START=$"Starting ${NAME} service: "
	echo -n "$SLON_START"
	$SU -l postgres -c "$SLONDAEMON $cluster_name $conn_info -f $SLONCONF &" >> "$SLONLOG" 2>&1 < /dev/null
	#$SU -l postgres -c "$SLONDAEMON -f $SLONCONF &" >> "$SLONLOG" 2>&1 < /dev/null
	sleep 2
	pid=`pidof -s "$SLONDAEMON"`
	if [ $pid ] 
	then
		success "$SLON_START"
		touch /usr/local/slony/${NAME}
		echo
	else
		failure "$PSQL_START"
		echo
		script_result=1
	fi
}

stop(){
	echo -n $"Stopping ${NAME} service: "
        if [ $UID -ne 0 ]; then
                RETVAL=1
                failure
        else
                killproc /usr/local/slony/bin/slon
                RETVAL=$?
                [ $RETVAL -eq 0 ] && rm -f /usr/local/slony/${NAME}
        fi;
        echo
        return $RETVAL
}

restart(){
    stop
    start
}

condrestart(){
    [ -e /usr/local/slony/${NAME} ] && restart
}

condstop(){
    [ -e /usr/local/slony/${NAME} ] && stop
}

# See how we were called.
case "$1" in
  start)
        start
        ;;
  stop)
        stop
        ;;
  status)
        status slon
        script_result=$?
        ;;
  restart)
        restart
        ;;
  condrestart)
        condrestart
        ;;
  condstop)
        condstop
        ;;
  *)
        echo $"Usage: $0 {start|stop|status|restart|condrestart|condstop}"
        exit 1
esac

exit $script_result

3、slonik完整脚本

#!/bin/sh

export PGBASE=/usr/local/pg945
export PGDATA=$PGBASE/data
export PGUSER=postgres
export PGPORT=5432
export PATH=$PATH:$PGBASE/bin:$HOME/bin:/usr/local/slony/bin
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$PGBASE/lib
export SLON_CONF=/usr/local/slony/etc/slon.conf

cluster_name=slony
master_conninfo="host=ha1 dbname=slony user=slony"
slave_conninfo="host=ha2 dbname=slony user=slony"
cluster_log=/usr/local/slony/log

function cluster
{
slonik <<EOF
cluster name = $cluster_name;
node 1 admin conninfo = '$master_conninfo';
init cluster (id = 1,comment = 'master');
EOF
}

function node
{
slonik <<EOF
cluster name = $cluster_name;
node 1 admin conninfo = '$master_conninfo';
node 2 admin conninfo = '$slave_conninfo';
store node (id = 2,comment = 'slave',event node = 1);
EOF
}

function path
{
slonik <<EOF
cluster name = $cluster_name;
node 1 admin conninfo = '$master_conninfo';
node 2 admin conninfo = '$slave_conninfo';
store path (server = 1,client = 2,conninfo = '$master_conninfo');
store path (server = 2,client = 1,conninfo = '$slave_conninfo');
EOF
}

function listen
{
slonik <<EOF
cluster name = $cluster_name;
node 1 admin conninfo = '$master_conninfo';
node 2 admin conninfo = '$slave_conninfo';
store listen (origin = 1, provider = 1, receiver = 2);
EOF
slonik <<EOF
cluster name = $cluster_name;
node 1 admin conninfo = '$master_conninfo';
node 2 admin conninfo = '$slave_conninfo';
store listen (origin = 2, provider = 2, receiver = 1);
EOF
}

function set_origin
{
slonik <<EOF
cluster name = $cluster_name;
node 1 admin conninfo = '$master_conninfo';
node 2 admin conninfo = '$slave_conninfo';
create set (id = 1,origin = 1,comment = '1to2');
EOF
}

function table
{
slonik <<EOF
cluster name = $cluster_name;
node 1 admin conninfo = '$ha1_conninfo';
node 2 admin conninfo = '$ha2_conninfo';
set add table (set id = 1,origin = 1,fully qualified name='slony.tb1',comment='ha1toha2');
EOF
}

function set_receive
{
slonik <<EOF
cluster name = $cluster_name;
node 1 admin conninfo = '$master_conninfo';
node 2 admin conninfo = '$slave_conninfo';
subscribe set (id = 1,provider = 1,receiver = 2,forward = no,omit copy = no);
EOF
}

cluster
node
path
listen
set_origin
table
set_receive