连接被拒绝（PGError）（postgresql和rails）

当我尝试使用“$ rails s”运行我的localhost时，我一直收到此错误：

（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）**用自制软件安装

我一直在做很多卸载postgresql并重新安装，所以我有预感，某些地方可能存在冲突的库……我只是不知道从哪里开始。

我在同一个文件夹中安装了Postgresql 9.1和9.2，只是将9.1移到垃圾箱中。

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 ' 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 ' 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 `' 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 ' 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 `' 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 ' 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 `' from script/rails:6:in `require' from script/rails:6:in `' 

Answer 1

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? 

港口

您可能正在尝试连接到错误的端口。
标准端口是5432 。 检查你是如何（以及是否）启动你的postgres服务器：

 postgres@db:~$ ps -auxww | grep ^postgres ...  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 

手册中有相关信息。

在我的示例中，使用了/etc/postgresql/9.1/main/postgresql.conf设置，其中说（在许多其他设置中）：

 port = 5432 

或者跑

 netstat -nlp | grep postgres 

或者只看这里（至少在Debian或Ubuntu中）：

 ls -lA /var/run/postgresql/ 

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

listen_addresses

或者你只是忘了允许TCP / IP连接 。 这些相关答案中的更多信息：
– 使用psql命令运行批处理文件，无需密码
– pg_hba.conf中“local”和“localhost”连接类型之间有什么区别？
– 没有主机的pg_hba.conf条目

Answer 2

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 （而不是标准默认值5432 ）。

当我的Rails项目尝试连接到postgresql的默认端口时（因为端口未在database.yml文件中明确定义）并且保持失败，就会出现问题。 甚至在删除postgresql-9.4之后。

解决方案更改postgresql的配置文件

解决方案是更新postgresql（9.5）配置中的端口。 要执行此操作，请打开文件/etc/postgresql/9.5/main/postgresql.conf并更改该行

 port = 5433 # (change requires restart) 

至

 port = 5432 # (change requires restart) 

然后使用sudo service postgresql restart服务器。

更改Rails’“database.yml”文件的解决方案

或者，您可以通过显式提及新端口（即5433 ）来更改rails的database.yml文件，而无需更改postgresql的配置文件。 要做到这一点，只需添加这样的行

 port: 5433 

并重新启动rails服务器。

Answer 3

 sudo -u postgres pg_ctlcluster 9.3 main stop 

其次是

 sudo -u postgres pg_ctlcluster 9.3 main restart 

为我工作

Answer 4

在postgresql.conf中，/ var / lib / pgsql / data / postgresql.conf：
1.将listen_addresses =’localhost’更改为listen_addresses =’*’
2.启用默认端口5432，port = 5432
同样在pg_hba.conf，/ var / lib / pgsql / data /pg_hba.conf中：尝试将身份validation方法作为信任