连接被拒绝（PGError）（postgresql和rails）

Question

当我尝试使用“$rails”运行我的本地主机时，我一直收到这个错误：

（Mac OSX 10.8.3）（ruby 2.0.0p195（2013-05-14修订版40734）[x86_64-darwin12.3.0]）（Rails 3.2.11）（psql（PostgreSQL）9.2.2）**与自制软件一起安装

我一直在卸载postgresql并重新安装，所以我有一种预感，可能在某个地方有冲突的库……我只是不知道从哪里开始。

我将Postgreql 9.1和9.2放在同一个文件夹中，然后将9.1移到了垃圾桶中。

下面是我在终端中运行“rails s”时的输出

Danny$ rails s
^[b=> Booting Thin
=> Rails 3.2.11 application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
Exiting
/Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/postgresql_adapter.rb:1208:in `initialize': could        not connect to server: Connection refused (PGError)
Is the server running on host "localhost" (127.0.0.1) and accepting
TCP/IP connections on port 5433?
could not connect to server: Connection refused
Is the server running on host "localhost" (::1) and accepting
TCP/IP connections on port 5433?
could not connect to server: Connection refused
Is the server running on host "localhost" (fe80::1) and accepting
TCP/IP connections on port 5433?
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/postgresql_adapter.rb:1208:in `new'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/postgresql_adapter.rb:1208:in `connect'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/postgresql_adapter.rb:326:in `initialize'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `new'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/postgresql_adapter.rb:28:in `postgresql_connection'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/abstract/connection_pool.rb:315:in `new_connection'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/abstract/connection_pool.rb:325:in `checkout_new_connection'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/abstract/connection_pool.rb:247:in `block (2 levels) in checkout'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `loop'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `block in checkout'
from /Users/Danny/.rvm/rubies/ruby-2.0.0-p195/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/abstract/connection_pool.rb:239:in `checkout'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/abstract/connection_pool.rb:102:in `block in connection'
from /Users/Danny/.rvm/rubies/ruby-2.0.0-p195/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/abstract/connection_pool.rb:101:in `connection'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/abstract/connection_pool.rb:410:in `retrieve_connection'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/abstract/connection_specification.rb:171:in `retrieve_connection'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/connection_adapters/abstract/connection_specification.rb:145:in `connection'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/model_schema.rb:308:in `clear_cache!'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activerecord-3.2.11/lib/active_record/railtie.rb:97:in `block (2 levels) in <class:Railtie>'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activesupport-3.2.11/lib/active_support/callbacks.rb:418:in `_run__3642716200177086041__prepare__4186317719333288752__callbacks'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activesupport-3.2.11/lib/active_support/callbacks.rb:405:in `__run_callback'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activesupport-3.2.11/lib/active_support/callbacks.rb:385:in `_run_prepare_callbacks'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activesupport-3.2.11/lib/active_support/callbacks.rb:81:in `run_callbacks'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/actionpack-3.2.11/lib/action_dispatch/middleware/reloader.rb:74:in `prepare!'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/actionpack-3.2.11/lib/action_dispatch/middleware/reloader.rb:48:in `prepare!'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.11/lib/rails/application/finisher.rb:47:in `block in <module:Finisher>'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.11/lib/rails/initializable.rb:30:in `instance_exec'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.11/lib/rails/initializable.rb:30:in `run'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.11/lib/rails/initializable.rb:55:in `block in run_initializers'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.11/lib/rails/initializable.rb:54:in `each'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.11/lib/rails/initializable.rb:54:in `run_initializers'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.11/lib/rails/application.rb:136:in `initialize!'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.11/lib/rails/railtie/configurable.rb:30:in `method_missing'
from /Users/Danny/Dropbox/programming/coding/f_app/config/environment.rb:7:in `<top (required)>'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activesupport-3.2.11/lib/active_support/dependencies.rb:251:in `require'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activesupport-3.2.11/lib/active_support/dependencies.rb:251:in `block in require'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activesupport-3.2.11/lib/active_support/dependencies.rb:236:in `load_dependency'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/activesupport-3.2.11/lib/active_support/dependencies.rb:251:in `require'
from /Users/Danny/Dropbox/programming/coding/f_app/config.ru:3:in `block in <main>'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/rack-1.4.5/lib/rack/builder.rb:51:in `instance_eval'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/rack-1.4.5/lib/rack/builder.rb:51:in `initialize'
from /Users/Danny/Dropbox/programming/coding/f_app/config.ru:in `new'
from /Users/Danny/Dropbox/programming/coding/f_app/config.ru:in `<main>'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/rack-1.4.5/lib/rack/builder.rb:40:in `eval'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/rack-1.4.5/lib/rack/builder.rb:40:in `parse_file'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/rack-1.4.5/lib/rack/server.rb:200:in `app'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.11/lib/rails/commands/server.rb:46:in `app'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/rack-1.4.5/lib/rack/server.rb:304:in `wrapped_app'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/rack-1.4.5/lib/rack/server.rb:254:in `start'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.11/lib/rails/commands/server.rb:70:in `start'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.11/lib/rails/commands.rb:55:in `block in <top (required)>'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.11/lib/rails/commands.rb:50:in `tap'
from /Users/Danny/.rvm/gems/ruby-2.0.0-p195/gems/railties-3.2.11/lib/rails/commands.rb:50:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'

Answer 1

匿名用户

在我的例子中，问题是由Ubuntu 16.04中的postgresql-9.4升级到postgressql-9.5引起的。由于在某个时间点安装了两个版本，后来安装的版本，即postgresql-9.5的配置更改为默认端口5433（而不是标准默认的5432）。

当我的Rails项目试图连接到postgreql的默认端口时，出现了问题（因为端口没有在database.yml文件中明确定义），并且一直失败。

解决方案是在更新的postgresql (9.5)的配置中更改端口。为此，请打开文件< code >/etc/PostgreSQL/9.5/main/PostgreSQL . conf 并更改该行

port = 5433                             # (change requires restart)

自

port = 5432                             # (change requires restart)

然后使用< code > sudo service PostgreSQL restart 重新启动服务器。

或者，您可以更改rails的＜code＞数据库。在不更改postgresql的配置文件的情况下，通过显式提及新端口（即5433）来创建ymlfile。为此，只需添加一行，如下所示

port: 5433

并重新启动rails服务器。

Answer 2

这可能会解决问题：-

>

在 sql 提示符下使用命令 SHOW config_file; 和 SHOW hba_file; 获取 hba.conf 文件地址

现在打开hba.conf并添加此主机所有0.0.0.0/0信任

现在打开postgresql.conf并添加listen_address = '*'

Answer 3

错误消息是有用的:

could not connect to server: Connection refused
Is the server running on host "localhost" (::1) and accepting
TCP/IP connections on port 5433?

您可能试图连接到错误的端口。
标准端口为5432。请检查您是如何（以及是否）启动postgres服务器的：

postgres@db:~$ ps -auxww | grep ^postgres
... <stripped more lines>
postgres  1274  0.0  0.3 1437240 57308 ?       S    May27   5:01 /usr/lib/postgresql/9.1/bin/postgres -D /var/lib/postgresql/9.1/main -c config_file=/etc/postgresql/9.1/main/postgresql.conf

手册这里有相关信息。

在我的示例中，/etc/postgresql/9.1/main/postgresql中的设置。conf＜/code＞被使用，它表示（在许多其他设置中）：

port = 5432

或运行：

netstat -nlp | grep postgres

或者看看这里（至少在 Debian 或 Ubuntu 中）：

ls -lA /var/run/postgresql/

如果创建新的数据库集群，PostgreSQL会选择下一个空闲端口。由于您重复安装，您可能会混淆端口号。

或者您只是忘记允许TCP / IP连接。相关答案：

• 使用不带密码的psql命令运行批处理文件
• pg_hba.conf?中的"本地"和"localhost"连接类型有什么区别
• 主机没有pg_hba.conf条目