Slony是PostgreSQL领域中最广泛的复制解决方案之一。它不仅是最古老的复制实现之一，它也是一个拥有最广泛的外部工具支持的工具，比如pgAdmin3。多年来，Slony是在PostgreSQL中复制数据的惟一可行的解决方案。Slony使用逻辑复制；Slony-I一般要求表有主键,或者唯一键；Slony的工作不是基于PostgreSQL事务日志的；而是基于触发器的；基于逻辑复制高可用性；PostgreSQL除了slony；还有Londiste,BDR等等后续文章会讲到

1. 安装Slony

　　下载地址：http://www.slony.info；安装步骤:

# tar -jxvf slony1-2.2.5.tar.bz2

# cd slony1-2.2.5

# ./configure --with-pgconfigdir=/opt/pgsql96/bin

# make

# make install

　　安装完成！
　　执行./configure时；会在当前目录是否可以找到pg_config命令；本例pg_config在/opt/pgsql96/bin目录下；

2. Slony架构图

3. 复制表

现有实验环境：

主机名 IP 角色
PostgreSQL201 192.168.1.201 master
PostgreSQL202 192.168.1.202 slave

3.1 在两台数据库中都创建一个slony的超级用户；专为slony服务

create user slony superuser password 'li0924';

3.2  本实验两台主机都有lottu数据库；以lottu数据库中的表作为实验对象；在两个数据库中以相同的方式创建该表synctab，因为表结构不会自动复制。

create table synctab(id int primary key,name text);

3.3  在所有节点设置允许Slony-I用户远程登录；在pg_hba.conf文件添加

host    all             slony             192.168.1.0/24        trust

3.4 设置slony(在master主机操作)

　　编写一个slonik脚本用于注册这些节点的脚本如下所示：

[postgres@Postgres201 ~]$ cat slony_setup.sh

#!/bin/sh

MASTERDB=lottu

SLAVEDB=lottu

HOST1=192.168.1.201

HOST2=192.168.1.202

DBUSER=slony

slonik<<_EOF_

cluster name = first_cluster;

# define nodes (this is needed by pretty much

# all slonik scripts)

node  admin conninfo = 'dbname=$MASTERDB host=$HOST1 user=$DBUSER';

node  admin conninfo = 'dbname=$SLAVEDB host=$HOST2 user=$DBUSER';

# init cluster

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

# group tables into sets

create set (id=, origin=, comment='Our tables');

set add table (set id=, origin=, id=, fully qualified name = 'lottu.synctab', comment='sample table');

store node (id=, comment = 'Slave node', event node=);

store path (server = , client = , conninfo='dbname=$MASTERDB host=$HOST1 user=$DBUSER');

store path (server = , client = , conninfo='dbname=$SLAVEDB host=$HOST2 user=$DBUSER');

_EOF_

　　现在这个表在Slony的控制下，我们可以开始订阅脚本如下所示：

[postgres@Postgres201 ~]$ cat slony_subscribe.sh

#!/bin/sh

MASTERDB=lottu

SLAVEDB=lottu

HOST1=192.168.1.201

HOST2=192.168.1.202

DBUSER=slony

slonik<<_EOF_

cluster name = first_cluster;

node  admin conninfo = 'dbname=$MASTERDB host=$HOST1 user=$DBUSER';

node  admin conninfo = 'dbname=$SLAVEDB host=$HOST2 user=$DBUSER';

subscribe set ( id = , provider = , receiver = , forward = no);

_EOF_

　　在master主机执行脚本

[postgres@Postgres201 ~]$ ./slony_setup.sh

[postgres@Postgres201 ~]$ ./slony_subscribe.sh &

[]

　　定义了我们想要复制的东西之后，我们可以在每台主机启动slon守护进程

slon first_cluster 'host=192.168.1.201 dbname=lottu user=slony' &

slon first_cluster 'host=192.168.1.202 dbname=lottu user=slony' &

3.5 验证slony-I是否配置成功？

　　在master主机执行dml操作

[postgres@Postgres201 ~]$ psql lottu lottu

psql (9.6.0)

Type "help" for help.

lottu=# \d synctab

    Table "lottu.synctab"

 Column |  Type   | Modifiers

--------+---------+-----------

 id     | integer | not null

 name   | text    |

Indexes:

    "synctab_pkey" PRIMARY KEY, btree (id)

Triggers:

    _first_cluster_logtrigger AFTER INSERT OR DELETE OR UPDATE ON synctab FOR EACH ROW EXECUTE PROCEDURE _first_cluster.logtrigger('_first_cluster', '', 'k')

    _first_cluster_truncatetrigger BEFORE TRUNCATE ON synctab FOR EACH STATEMENT EXECUTE PROCEDURE _first_cluster.log_truncate('')

Disabled user triggers:

    _first_cluster_denyaccess BEFORE INSERT OR DELETE OR UPDATE ON synctab FOR EACH ROW EXECUTE PROCEDURE _first_cluster.denyaccess('_first_cluster')

    _first_cluster_truncatedeny BEFORE TRUNCATE ON synctab FOR EACH STATEMENT EXECUTE PROCEDURE _first_cluster.deny_truncate()

lottu=# insert into synctab values (1001,'lottu');

INSERT 0 1

　　在slave主机查看是否对应变化

[postgres@Postgres202 ~]$ psql

psql (9.6.0)

Type "help" for help.

postgres=# \c lottu lottu

You are now connected to database "lottu" as user "lottu".

lottu=> select * from synctab ;

  id  | name

------+-------

 1001 | lottu

(1 row)

4.  Slony-I相关表或者视图查看

4.1 配置成功；会在所在的数据库中生成一个schema

[postgres@Postgres201 ~]$ psql lottu lottu

psql (9.6.0)

Type "help" for help.

lottu=# \dn

      List of schemas

      Name      |  Owner

----------------+----------

 _first_cluster | slony

 lottu          | lottu

 public         | postgres

(3 rows)

4.2 查看集群中的节点信息

lottu=# select * from _first_cluster.sl_node;

 no_id | no_active | no_comment  | no_failed

-------+-----------+-------------+-----------

     1 | t         | Master Node | f

     2 | t         | Slave node  | f

(2 rows)

4.3 查看集群中的集合信息

lottu=# select * from _first_cluster.sl_set;

 set_id | set_origin | set_locked | set_comment

--------+------------+------------+-------------

      1 |          1 |            | Our tables

(1 row)

4.4 查看集群中的表信息

lottu=# select * from _first_cluster.sl_table;

-[ RECORD 1 ]-------------

tab_id      | 1

tab_reloid  | 57420

tab_relname | synctab

tab_nspname | lottu

tab_set     | 1

tab_idxname | synctab_pkey

tab_altered | f

tab_comment | sample table

5. 日常维护

5.1  Slony-I向现有集群中增加一个复制表

　　以表synctab2为例：

create table synctab2(id int primary key,name text,reg_time timestamp);

　　我们要创建一个新的表格集;脚本是这样的

[postgres@Postgres201 ~]$ cat slony_add_table_set.sh

#!/bin/sh

MASTERDB=lottu

SLAVEDB=lottu

HOST1=192.168.1.201

HOST2=192.168.1.202

DBUSER=slony

slonik<<_EOF_

cluster name = first_cluster;

node  admin conninfo = 'dbname=$MASTERDB host=$HOST1 user=$DBUSER';

node  admin conninfo = 'dbname=$SLAVEDB host=$HOST2 user=$DBUSER';

create set (id=, origin=, comment='a second replication set');

set add table (set id=, origin=, id=, fully qualified name ='lottu.synctab2', comment='second table');

subscribe set(id=, provider=,receiver=);

subscribe set(id=, provider=,receiver=);

merge set(id=, add id=,origin=);

_EOF_

　　执行slony_add_table_set.sh脚本

[postgres@Postgres201 ~]$ ./slony_add_table_set.sh

<stdin>: subscription in progress before mergeSet. waiting

<stdin>: subscription in progress before mergeSet. waiting

　　查看是否添加成功

lottu=# select * from _first_cluster.sl_table;

-[ RECORD  ]--------------

tab_id      |

tab_reloid  |

tab_relname | synctab

tab_nspname | lottu

tab_set     |

tab_idxname | synctab_pkey

tab_altered | f

tab_comment | sample table

-[ RECORD  ]--------------

tab_id      |

tab_reloid  |

tab_relname | synctab2

tab_nspname | lottu

tab_set     |

tab_idxname | synctab2_pkey

tab_altered | f

tab_comment | second table

5.2  Slony-I向现有集群中删除一个复制表

[postgres@Postgres201 ~]$ cat slony_drop_table.sh

#!/bin/sh

MASTERDB=lottu

SLAVEDB=lottu

HOST1=192.168.1.201

HOST2=192.168.1.202

DBUSER=slony

slonik<<_EOF_

cluster name = first_cluster;

node  admin conninfo = 'dbname=$MASTERDB host=$HOST1 user=$DBUSER';

node  admin conninfo = 'dbname=$SLAVEDB host=$HOST2 user=$DBUSER';

set drop table (id=, origin=);

_EOF_

　　执行slony_drop_table.sh脚本

[postgres@Postgres201 ~]$ ./slony_drop_table.sh

　　查看是否删除成功

lottu=# select * from _first_cluster.sl_table;

 tab_id | tab_reloid | tab_relname | tab_nspname | tab_set | tab_idxname  | tab_altered | tab_comment

--------+------------+-------------+-------------+---------+--------------+-------------+--------------

      1 |      57420 | synctab     | lottu       |       1 | synctab_pkey | f           | sample table

(1 row)

5. 3删除slony

[postgres@Postgres201 ~]$ cat slony_drop_node.sh

#!/bin/sh

MASTERDB=lottu

SLAVEDB=lottu

HOST1=192.168.1.201

HOST2=192.168.1.202

DBUSER=slony

slonik<<_EOF_

cluster name = first_cluster;

node  admin conninfo = 'dbname=$MASTERDB host=$HOST1 user=$DBUSER';

node  admin conninfo = 'dbname=$SLAVEDB host=$HOST2 user=$DBUSER';

uninstall node (id = );

uninstall node (id = );

_EOF_

　　执行脚本如下：

[postgres@Postgres201 ~]$ ./slony_drop_node.sh

<stdin>:: NOTICE:  Slony-I: Please drop schema "_first_cluster"

<stdin>:: NOTICE:  drop cascades to  other objects

DETAIL:  drop cascades to table _first_cluster.sl_node

drop cascades to table _first_cluster.sl_nodelock

drop cascades to table _first_cluster.sl_set

drop cascades to table _first_cluster.sl_setsync

drop cascades to table _first_cluster.sl_table

drop cascades to table _first_cluster.sl_sequence

drop cascades to table _first_cluster.sl_path

drop cascades to table _first_cluster.sl_listen

drop cascades to table _first_cluster.sl_subscribe

drop cascades to table _first_cluster.sl_event

drop cascades to table _first_cluster.sl_confirm

drop cascades to table _first_cluster.sl_seqlog

drop cascades to function _first_cluster.sequencelastvalue(text)

drop cascades to table _first_cluster.sl_log_1

drop cascades to table _first_cluster.sl_log_2

drop cascades to table _first_cluster.sl_log_script

drop cascades to table _first_cluster.sl_registry

drop cascades to table _first_cluster.sl_apply_stats

drop cascades to view _first_cluster.sl_seqlastvalue

drop cascades to view _first_cluster.sl_failover_targets

drop cascades to sequence _first_cluster.sl_local_node_id

drop cascades to sequence _first_cluster.sl_event_seq

drop cascades to sequence _first_cluster.sl_action_seq

drop cascades to sequence _first_cluster.sl_log_status

drop cascades to table _first_cluster.sl_config_lock

drop cascades to table _first_cluster.sl_event_lock

drop cascades to table _first_cluster.sl_archive_counter

drop cascades to table _first_cluster.sl_components

drop cascades to type _first_cluster.vactables

drop cascades to function _first_cluster.createevent(name,text)

drop cascades to function _first_cluster.createevent(name,text,text)

drop cascades to function _first_cluster.createevent(name,text,text,text)

drop cascades to function _first_cluster.createevent(name,text,text,text,text)

drop cascades to function _first_cluster.createevent(name,text,text,text,text,text)

drop cascades to function _first_cluster.createevent(name,text,text,text,text,text,text)

drop cascades to function _first_cluster.createevent(name,text,text,text,text,text,text,text)

drop cascades to function _first_cluster.createevent(name,text,text,text,text,text,text,text,text)

drop cascades to function _first_cluster.createevent(name,text,text,text,text,text,text,text,text,text)

drop cascades to function _first_cluster.denyaccess()

drop cascades to trigger _first_cluster_denyaccess on table lottu.synctab

drop cascades to function _first_cluster.lockedset()

drop cascades to function _first_cluster.getlocalnodeid(name)

drop cascades to function _first_cluster.getmoduleversion()

drop cascades to function _first_cluster.resetsession()

drop cascades to function _first_cluster.logapply()

drop cascades to function _first_cluster.logapplysetcachesize(integer)

drop cascades to function _first_cluster.logapplysavestats(name,integer,interval)

drop cascades to function _first_cluster.checkmoduleversion()

drop cascades to function _first_cluster.decode_tgargs(bytea)

drop cascades to function _first_cluster.logtrigger()

drop cascades to trigger _first_cluster_logtrigger on table lottu.synctab

drop cascades to function _first_cluster.terminatenodeconnections(integer)

drop cascades to function _first_cluster.killbackend(integer,text)

drop cascades to function _first_cluster.seqtrack(integer,bigint)

drop cascades to function _first_cluster.slon_quote_brute(text)

drop cascades to function _first_cluster.slon_quote_input(text)

drop cascades to function _first_cluster.slonyversionmajor()

drop cascades to function _first_cluster.slonyversionminor()

drop cascades to function _first_cluster.slonyversionpatchlevel()

drop cascades to function _first_cluster.slonyversion()

drop cascades to function _first_cluster.registry_set_int4(text,integer)

drop cascades to function _first_cluster.registry_get_int4(text,integer)

drop cascades to function _first_cluster.registry_set_text(text,text)

drop cascades to function _first_cluster.registry_get_text(text,text)

drop cascades to function _first_cluster.registry_set_timestamp(text,timestamp with time zone)

drop cascades to function _first_cluster.registry_get_timestamp(text,timestamp with time zone)

drop cascades to function _first_cluster.cleanupnodelock()

drop cascades to function _first_cluster.registernodeconnection(integer)

drop cascades to function _first_cluster.initializelocalnode(integer,text)

drop cascades to function _first_cluster.storenode(integer,text)

drop cascades to function _first_cluster.storenode_int(integer,text)

drop cascades to function _first_cluster.enablenode(integer)

drop cascades to function _first_cluster.enablenode_int(integer)

drop cascades to function _first_cluster.disablenode(integer)

drop cascades to function _first_cluster.disablenode_int(integer)

drop cascades to function _first_cluster.dropnode(integer[])

drop cascades to function _first_cluster.dropnode_int(integer)

drop cascades to function _first_cluster.prefailover(integer,boolean)

drop cascades to function _first_cluster.failednode(integer,integer,integer[])

drop cascades to function _first_cluster.failednode2(integer,integer,bigint,integer[])

drop cascades to function _first_cluster.failednode3(integer,integer,bigint)

drop cascades to function _first_cluster.failoverset_int(integer,integer,bigint)

drop cascades to function _first_cluster.uninstallnode()

drop cascades to function _first_cluster.clonenodeprepare(integer,integer,text)

drop cascades to function _first_cluster.clonenodeprepare_int(integer,integer,text)

drop cascades to function _first_cluster.clonenodefinish(integer,integer)

drop cascades to function _first_cluster.storepath(integer,integer,text,integer)

drop cascades to function _first_cluster.storepath_int(integer,integer,text,integer)

drop cascades to function _first_cluster.droppath(integer,integer)

drop cascades to function _first_cluster.droppath_int(integer,integer)

drop cascades to function _first_cluster.storelisten(integer,integer,integer)

drop cascades to function _first_cluster.storelisten_int(integer,integer,integer)

drop cascades to function _first_cluster.droplisten(integer,integer,integer)

drop cascades to function _first_cluster.droplisten_int(integer,integer,integer)

drop cascades to function _first_cluster.storeset(integer,text)

drop cascades to function _first_cluster.storeset_int(integer,integer,text)

drop cascades to function _first_cluster.lockset(integer)

drop cascades to function _first_cluster.unlockset(integer)

drop cascades to function _first_cluster.moveset(integer,integer)

drop cascades to function _first_cluster.moveset_int(integer,integer,integer,bigint)

and  other objects (see server log for list)

<stdin>:: NOTICE:  Slony-I: Please drop schema "_first_cluster"

<stdin>:: NOTICE:  drop cascades to  other objects

DETAIL:  drop cascades to table _first_cluster.sl_node

drop cascades to table _first_cluster.sl_nodelock

drop cascades to table _first_cluster.sl_set

drop cascades to table _first_cluster.sl_setsync

drop cascades to table _first_cluster.sl_table

drop cascades to table _first_cluster.sl_sequence

drop cascades to table _first_cluster.sl_path

drop cascades to table _first_cluster.sl_listen

drop cascades to table _first_cluster.sl_subscribe

drop cascades to table _first_cluster.sl_event

drop cascades to table _first_cluster.sl_confirm

drop cascades to table _first_cluster.sl_seqlog

drop cascades to function _first_cluster.sequencelastvalue(text)

drop cascades to table _first_cluster.sl_log_1

drop cascades to table _first_cluster.sl_log_2

drop cascades to table _first_cluster.sl_log_script

drop cascades to table _first_cluster.sl_registry

drop cascades to table _first_cluster.sl_apply_stats

drop cascades to view _first_cluster.sl_seqlastvalue

drop cascades to view _first_cluster.sl_failover_targets

drop cascades to sequence _first_cluster.sl_local_node_id

drop cascades to sequence _first_cluster.sl_event_seq

drop cascades to sequence _first_cluster.sl_action_seq

drop cascades to sequence _first_cluster.sl_log_status

drop cascades to table _first_cluster.sl_config_lock

drop cascades to table _first_cluster.sl_event_lock

drop cascades to table _first_cluster.sl_archive_counter

drop cascades to table _first_cluster.sl_components

drop cascades to type _first_cluster.vactables

drop cascades to function _first_cluster.createevent(name,text)

drop cascades to function _first_cluster.createevent(name,text,text)

drop cascades to function _first_cluster.createevent(name,text,text,text)

drop cascades to function _first_cluster.createevent(name,text,text,text,text)

drop cascades to function _first_cluster.createevent(name,text,text,text,text,text)

drop cascades to function _first_cluster.createevent(name,text,text,text,text,text,text)

drop cascades to function _first_cluster.createevent(name,text,text,text,text,text,text,text)

drop cascades to function _first_cluster.createevent(name,text,text,text,text,text,text,text,text)

drop cascades to function _first_cluster.createevent(name,text,text,text,text,text,text,text,text,text)

drop cascades to function _first_cluster.denyaccess()

drop cascades to trigger _first_cluster_denyaccess on table lottu.synctab

drop cascades to function _first_cluster.lockedset()

drop cascades to function _first_cluster.getlocalnodeid(name)

drop cascades to function _first_cluster.getmoduleversion()

drop cascades to function _first_cluster.resetsession()

drop cascades to function _first_cluster.logapply()

drop cascades to function _first_cluster.logapplysetcachesize(integer)

drop cascades to function _first_cluster.logapplysavestats(name,integer,interval)

drop cascades to function _first_cluster.checkmoduleversion()

drop cascades to function _first_cluster.decode_tgargs(bytea)

drop cascades to function _first_cluster.logtrigger()

drop cascades to trigger _first_cluster_logtrigger on table lottu.synctab

drop cascades to function _first_cluster.terminatenodeconnections(integer)

drop cascades to function _first_cluster.killbackend(integer,text)

drop cascades to function _first_cluster.seqtrack(integer,bigint)

drop cascades to function _first_cluster.slon_quote_brute(text)

drop cascades to function _first_cluster.slon_quote_input(text)

drop cascades to function _first_cluster.slonyversionmajor()

drop cascades to function _first_cluster.slonyversionminor()

drop cascades to function _first_cluster.slonyversionpatchlevel()

drop cascades to function _first_cluster.slonyversion()

drop cascades to function _first_cluster.registry_set_int4(text,integer)

drop cascades to function _first_cluster.registry_get_int4(text,integer)

drop cascades to function _first_cluster.registry_set_text(text,text)

drop cascades to function _first_cluster.registry_get_text(text,text)

drop cascades to function _first_cluster.registry_set_timestamp(text,timestamp with time zone)

drop cascades to function _first_cluster.registry_get_timestamp(text,timestamp with time zone)

drop cascades to function _first_cluster.cleanupnodelock()

drop cascades to function _first_cluster.registernodeconnection(integer)

drop cascades to function _first_cluster.initializelocalnode(integer,text)

drop cascades to function _first_cluster.storenode(integer,text)

drop cascades to function _first_cluster.storenode_int(integer,text)

drop cascades to function _first_cluster.enablenode(integer)

drop cascades to function _first_cluster.enablenode_int(integer)

drop cascades to function _first_cluster.disablenode(integer)

drop cascades to function _first_cluster.disablenode_int(integer)

drop cascades to function _first_cluster.dropnode(integer[])

drop cascades to function _first_cluster.dropnode_int(integer)

drop cascades to function _first_cluster.prefailover(integer,boolean)

drop cascades to function _first_cluster.failednode(integer,integer,integer[])

drop cascades to function _first_cluster.failednode2(integer,integer,bigint,integer[])

drop cascades to function _first_cluster.failednode3(integer,integer,bigint)

drop cascades to function _first_cluster.failoverset_int(integer,integer,bigint)

drop cascades to function _first_cluster.uninstallnode()

drop cascades to function _first_cluster.clonenodeprepare(integer,integer,text)

drop cascades to function _first_cluster.clonenodeprepare_int(integer,integer,text)

drop cascades to function _first_cluster.clonenodefinish(integer,integer)

drop cascades to function _first_cluster.storepath(integer,integer,text,integer)

drop cascades to function _first_cluster.storepath_int(integer,integer,text,integer)

drop cascades to function _first_cluster.droppath(integer,integer)

drop cascades to function _first_cluster.droppath_int(integer,integer)

drop cascades to function _first_cluster.storelisten(integer,integer,integer)

drop cascades to function _first_cluster.storelisten_int(integer,integer,integer)

drop cascades to function _first_cluster.droplisten(integer,integer,integer)

drop cascades to function _first_cluster.droplisten_int(integer,integer,integer)

drop cascades to function _first_cluster.storeset(integer,text)

drop cascades to function _first_cluster.storeset_int(integer,integer,text)

drop cascades to function _first_cluster.lockset(integer)

drop cascades to function _first_cluster.unlockset(integer)

drop cascades to function _first_cluster.moveset(integer,integer)

drop cascades to function _first_cluster.moveset_int(integer,integer,integer,bigint)

and  other objects (see server log for list)

　　完美；一切归零！

查考文献

https://www.cnblogs.com/ilifeilong/p/7009322.html

https://www.cnblogs.com/gaojian/p/3196244.html

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