连接被拒绝 (PGError) (postgresql 和 rails)

Question

当我尝试使用“$rails s”运行本地主机时，我不断收到此错误：

（Mac OSX 10.8.3） （红宝石 2.0.0p195（2013-05-14 修订版 40734）[x86_64-darwin12.3.0]） （轨道 3.2.11） (psql (PostgreSQL) 9.2.2 ) **随自制软件安装

我一直在卸载 postgresql 并重新安装，所以我预感到某处可能存在冲突的库……我只是不知道从哪里开始。

我在同一个文件夹中有 Postgresql 9.1 和 9.2，只是将 9.1 移到了垃圾箱中。

这是我在终端中运行“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

错误信息是有帮助的：

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

端口

您可能尝试连接到错误的端口。
标准端口是5432。检查您是如何（以及是否）启动了您的 postgres 服务器：

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

The manual has related information here.

在我的示例中，使用了来自 /etc/postgresql/9.1/main/postgresql.conf 的设置，它表示（在许多其他设置中）：

port = 5432

或运行：

netstat -nlp | grep postgres

或者只看这里（至少在 Debian 或 Ubuntu 中）：

ls -lA /var/run/postgresql/

如果您创建一个新的数据库集群，PostgreSQL 会选择下一个空闲端口。由于您重复安装，您可能混淆了端口号。

listen_addresses

或者你只是forgot to allow TCP/IP connections。相关答案：

• Run batch file with psql command without password
• What's the difference between "local" and "localhost" connection types in pg_hba.conf?
• no pg_hba.conf entry for host

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并添加这个host all all 0.0.0.0/0 trust

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

Answer 3

在我的情况下，问题是由 Ubuntu 16.04 中的 postgresql-9.4 升级到 postgresql-9.5 引起的。因为，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 项目尝试连接到 postgresql 的默认端口（因为该端口未在 database.yml 文件中明确定义）并一直失败时，出现了问题。即使在删除 postgresql-9.4 之后。

解决办法修改postgresql的配置文件

解决方案是更改更新后的 postgresql (9.5) 配置中的端口。为此，请打开文件 /etc/postgresql/9.5/main/postgresql.conf 并更改行

port = 5433                             # (change requires restart)

到

port = 5432                             # (change requires restart)

然后用sudo service postgresql restart重启服务器。

更改 Rails 的 `database.yml' 文件的解决方案

或者，您可以通过明确提及新端口（即5433）来更改rails 的database.yml 文件，而无需更改postgresql 的配置文件。为此，只需添加这样的一行

port: 5433

并重新启动 rails 服务器。

Answer 4

sudo -u postgres pg_ctlcluster 9.3 main stop

紧随其后

sudo -u postgres pg_ctlcluster 9.3 main restart

为我工作

Answer 5

我在连接到 Jira（从 Jira 端）时收到此错误消息，解决方案是更改“数据库服务器的主机名或 IP 地址”。到“本地主机”。如果您在本地运行，则不能只输入本地 IP 地址。

本地安装的下一个问题是密码总是失败，即使这是正确的，因为 pg_hba.conf 需要编辑，因此身份验证方法是“信任”。

Answer 6

在 postgresql.conf 中，/var/lib/pgsql/data/postgresql.conf：

1. 更改listen_addresses = 'localhost' to listen_addresses = '*'

2. 启用默认端口为5432，port = 5432

同样在 pg_hba.conf, /var/lib/pgsql/data/pg_hba.conf, 尝试将身份验证方法设为信任