PostgreSQL:基本的 pglogical 配置困难

PostgreSQL: difficulties with basic pglogical configuration

我发现 official pglogical documentation 非常混乱。不明白的事情太多了。也许之前配置过 pglogical 的人可以解释如何设置基本的逻辑复制。

有两个 PostgreSQL 9.5 实例 - 10.128.0.8 (archlinux1) 和 10.128.0.9 (archlinux2)。扩展已安装,CREATE EXTENSION 成功。每个实例上都有一个 table:

create table test (k text primary key, v text);

我想将它从 archlinux1 复制到 archlinux2。

根据文档,我应该创建一个提供者节点:

SELECT pglogical.create_node(
    node_name := 'provider1',
    dsn := 'host=providerhost port=5432 dbname=db'
);

应该在master上执行吗? providerhost 应该是 127.0.0.1 还是 10.128.0.8? Currenlty 复制只允许从本地主机(根据文档) - 它应该改变吗?我最好的猜测 - 它应该像这样在 master 上执行:

SELECT pglogical.create_node(
    node_name := 'provider1',
    dsn := 'host=127.0.0.1 port=5432 dbname=eax'
);
 create_node 
-------------
  2976894835
(1 row)

下一个:

SELECT pglogical.replication_set_add_all_tables('default', ARRAY['public']);

它应该在主服务器、副本服务器或两者上执行吗?我最好的猜测 - 仅在 master 上:

SELECT pglogical.replication_set_add_all_tables('default', ARRAY['public']);
 replication_set_add_all_tables 
--------------------------------
 t
(1 row)

下一个:

SELECT pglogical.create_node(
    node_name := 'subscriber1',
    dsn := 'host=thishost port=5432 dbname=db'
);

显然应该在副本上执行:

SELECT pglogical.create_node(
    node_name := 'subscriber1',
    dsn := 'host=127.0.0.1 port=5432 dbname=eax'
);
 create_node 
-------------
   330520249
(1 row)

下一步:

SELECT pglogical.create_subscription(
    subscription_name := 'subscription1',
    provider_dsn := 'host=providerhost port=5432 dbname=db'
);

最佳猜测 - 像这样在副本上执行它:

SELECT pglogical.create_subscription(
    subscription_name := 'subscription1',
    provider_dsn := 'host=10.128.0.8 port=5432 dbname=eax'
);
ERROR:  could not connect to the postgresql server: could not connect to server: Connection refused
    Is the server running on host "10.128.0.8" and accepting
    TCP/IP connections on port 5432?

DETAIL:  dsn was:  host=10.128.0.8 port=5432 dbname=eax

糟糕。好的,在 master 上正确修改 pg_hba.conf 和 postgresql.conf:

# pg_hba.conf
host    all    all    10.128.0.0/16    md5
# postgresql.conf
listen_addresses = 'localhost,10.128.0.8

仍然没有运气:

# SELECT pglogical.create_subscription(
    subscription_name := 'subscription1',
    provider_dsn := 'host=10.128.0.8 port=5432 dbname=eax user=eax password=qwerty'
);
ERROR:  could not connect to the postgresql server in replication mode: FATAL:  no pg_hba.conf entry for replication connection from host "10.128.0.9", user "eax", SSL off

DETAIL:  dsn was:  host=10.128.0.8 port=5432 dbname=eax user=eax password=qwerty

添加到 pg_hba.conf 主节点:

host    replication     eax        10.128.0.0/16            md5

在副本上(成功!):

SELECT pglogical.create_subscription(
    subscription_name := 'subscription1',
    provider_dsn := 'host=10.128.0.8 port=5432 dbname=eax user=eax password=qwerty'
);
 create_subscription 
---------------------
          1763399739
(1 row)

现在掌握:

eax=# insert into test values ('aaa', 'bbb');
INSERT 0 1
eax=# select * from test;
  k  |  v  
-----+-----
 aaa | bbb
(1 row)

在副本上:

eax=# select * from test;
 k | v 
---+---
(0 rows)

自然不行。日志中没有任何帮助。有什么建议吗?

UPD:我还在 pglogical 问题跟踪器中创建了一个 corresponding issue

也许这是一个更好的指南:http://bonesmoses.org/2016/10/14/pg-phriday-perfectly-logical/ - 至少它告诉您要在哪些节点上执行每个命令。

Depesz 发表了一篇关于 pglogical 配置的优秀博客 post https://www.depesz.com/2016/11/08/major-version-upgrading-with-minimal-downtime/

创建节点时需要指定外部 IP(不是本地主机)

供应商

SELECT pglogical.create_node(
node_name := 'provider1',
dsn := 'host=subscriberhost port=5432 dbname=db'
);

订阅者

SELECT pglogical.create_node(
node_name := 'subscriber1',
dsn := 'host=providerhost port=5432 dbname=eax'
);