PostgreSQL逻辑复制之slony的安装和使用

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

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 1 admin conninfo = 'dbname=$masterdb host=$host1 user=$dbuser';
node 2 admin conninfo = 'dbname=$slavedb host=$host2 user=$dbuser';
# init cluster
init cluster ( id=1, comment = 'master node');
# group tables into sets
create set (id=1, origin=1, comment='our tables');
set add table (set id=1, origin=1, id=1, fully qualified name = 'lottu.synctab', comment='sample table');
store node (id=2, comment = 'slave node', event node=1);
store path (server = 1, client = 2, conninfo='dbname=$masterdb host=$host1 user=$dbuser');
store path (server = 2, client = 1, conninfo='dbname=$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 1 admin conninfo = 'dbname=$masterdb host=$host1 user=$dbuser';
node 2 admin conninfo = 'dbname=$slavedb host=$host2 user=$dbuser';
subscribe set ( id = 1, provider = 1, receiver = 2, forward = no);
_eof_

　　在master主机执行脚本

[postgres@postgres201 ~]$ ./slony_setup.sh 
[postgres@postgres201 ~]$ ./slony_subscribe.sh &
[1] 1225

　　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', '1', 'k')
    _first_cluster_truncatetrigger before truncate on synctab for each statement execute procedure _first_cluster.log_truncate('1')
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 1 admin conninfo = 'dbname=$masterdb host=$host1 user=$dbuser';
node 2 admin conninfo = 'dbname=$slavedb host=$host2 user=$dbuser';
create set (id=2, origin=1, comment='a second replication set');
set add table (set id=2, origin=1, id=2, fully qualified name ='lottu.synctab2', comment='second table');
subscribe set(id=1, provider=1,receiver=2);
subscribe set(id=2, provider=1,receiver=2);
merge set(id=1, add id=2,origin=1);
_eof_

　　执行slony_add_table_set.sh脚本

[postgres@postgres201 ~]$ ./slony_add_table_set.sh 
:8 subscription in progress before mergeset. waiting
:8 subscription in progress before mergeset. waiting

　　查看是否添加成功

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
-[ record 2 ]--------------
tab_id      | 2
tab_reloid  | 57840
tab_relname | synctab2
tab_nspname | lottu
tab_set     | 1
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 1 admin conninfo = 'dbname=$masterdb host=$host1 user=$dbuser';
node 2 admin conninfo = 'dbname=$slavedb host=$host2 user=$dbuser';
set drop table (id=2, origin=1);
_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 1 admin conninfo = 'dbname=$masterdb host=$host1 user=$dbuser';
node 2 admin conninfo = 'dbname=$slavedb host=$host2 user=$dbuser';
uninstall node (id = 1);
uninstall node (id = 2);
_eof_

　　执行脚本如下：

[postgres@postgres201 ~]$ ./slony_drop_node.sh 
:4: notice:  slony-i: please drop schema "_first_cluster"
:4: notice:  drop cascades to 175 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 75 other objects (see server log for list)
:5: notice:  slony-i: please drop schema "_first_cluster"
:5: notice:  drop cascades to 175 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 75 other objects (see server log for list)

完美；一切归零！