服务器是在主机“localhost”（:: 1）上运行并在端口5432上接受TCP / IP连接吗？

Before anything, please note that I have found several similar questions on Stack Overflow and articles all over the web, but none of those helped me fix my issue:

在此之前，请注意我在Stack Overflow和网上的文章中发现了几个类似的问题，但这些都没有帮助我解决我的问题：

PG Error could not connect to server: Connection refused Is the server running on port 5432?
PG错误无法连接到服务器：连接被拒绝服务器是否在端口5432上运行？
PG::ConnectionBad - could not connect to server: Connection refused
PG :: ConnectionBad - 无法连接到服务器：连接被拒绝
psql: could not connect to server: Connection refused
psql：无法连接到服务器：连接被拒绝

Now, here is the issue:

现在，问题在于：

I have a Rails app that works like a charm.
我有一个Rails应用程序，就像一个魅力。
With my collaborator, we use GitHub to work together.
通过我的合作者，我们使用GitHub一起工作。
We have a master and an mvp branches.
我们有一个master和一个mvp分支。
I recently updated my git version with Homebrew (Mac).
我最近用Homebrew（Mac）更新了我的git版本。
We use Foreman to start our app locally.
我们使用Foreman在本地启动我们的应用程序。

Now, when I try to launch the app locally, I get the following error:

现在，当我尝试在本地启动应用程序时，出现以下错误：

PG::ConnectionBad at /
could not connect to server: Connection refused
    Is the server running on host "localhost" (::1) and accepting
    TCP/IP connections on port 5432?
could not connect to server: Connection refused
    Is the server running on host "localhost" (127.0.0.1) and accepting
    TCP/IP connections on port 5432?

I tried to reboot my computers several times.

我试图多次重启计算机。

I also checked the content of /usr/local/var/postgres:

我还检查了/ usr / local / var / postgres的内容：

PG_VERSION      pg_dynshmem     pg_multixact    pg_snapshots    pg_tblspc       postgresql.conf
base            pg_hba.conf     pg_notify       pg_stat         pg_twophase     postmaster.opts
global          pg_ident.conf   pg_replslot     pg_stat_tmp     pg_xlog         server.log
pg_clog         pg_logical      pg_serial       pg_subtrans     postgresql.auto.conf

As you can see, there is no postmaster.pid file in there.

如您所见，那里没有postmaster.pid文件。

Any idea how I could fix this?

知道如何解决这个问题吗？

10 个解决方案

#1

You most likely ran out of battery and your postgresql server didn't shutdown correctly.

你很可能没电了，你的postgresql服务器没有正确关机。

The easiest workaround is to download the official postgresql app and launch it: it will force the server to start (http://postgresapp.com/)

最简单的解决方法是下载官方postgresql应用程序并启动它：它将强制服务器启动（http://postgresapp.com/）

#2

run postgres -D /usr/local/var/postgres and you should see something like:

运行postgres -D / usr / local / var / postgres你应该看到类似的东西：

FATAL:  lock file "postmaster.pid" already exists
HINT:   Is another postmaster (PID 379) running in data directory "/usr/local/var/postgres"?

Then run kill -9 PID in HINT

然后在HINT中运行kill -9 PID

And you should be good to go.

你应该好好去。

#3

Most likely it's because your system shutdown unexpectedly

很可能是因为您的系统意外关闭

Try

尝试

postgres -D /usr/local/var/postgres

You might see

你可能会看到

FATAL:  lock file "postmaster.pid" already exists
HINT:  Is another postmaster (PID 449) running in data directory "/usr/local/var/postgres"?

Then try

然后试试

kill -9 PID

example

例

kill -9 419

And it should start postgres normally

它应该正常开始postgres

#4

It might be as simple as the postgresql service is down. Try running:

它可能就像postgresql服务失败一样简单。试试跑步：

sudo service postgresql start

which fixed the issue for me.

这解决了我的问题。

#5

This worked in my case:

这适用于我的情况：

brew uninstall postgresql
rm -fr /usr/local/var/postgres/
brew install postgresql

#6

I often encounter this problem on windows,the way I solved the problem is Service - Click PostgreSQL Database Server 8.3 - Click the second tab "log in" - choose the first line "the local system account".

我经常在Windows上遇到这个问题，我解决问题的方法是服务 - 点击PostgreSQL数据库服务器8.3 - 点击第二个标签“登录” - 选择第一行“本地系统帐户”。

#7

This worked for me: run

这对我有用：跑

sudo lsof -i :<port_number>

sudo lsof -i：

after that it will display the PID which is currently attached to the process.

之后它将显示当前附加到过程的PID。

After that run sudo kill -9 <PID>

之后运行sudo kill -9

if that doesn't work, try the solution offered by user8376606 it would definitely work!

如果这不起作用，尝试user8376606提供的解决方案，它肯定会工作！

#8

If you want to restart Postgresql on Linux, then you have to use the following command.

如果要在Linux上重新启动Postgresql，则必须使用以下命令。

/etc/init.d/postgresql restart

/etc/init.d/postgresql重启

#9

This can be as pid file created for postgress have not been deleted due to unexpected shutdown. So to fix this, remove this pid file.

这可以是因为意外关闭而没有删除为postgress创建的pid文件。因此，要解决此问题，请删除此pid文件。

Find the postgres data directory. On a MAC using homebrew it is /usr/local/var/postgres/, other systems it might be /usr/var/postgres/

找到postgres数据目录。在使用自制软件的MAC上，它是/ usr / local / var / postgres /，其他系统可能是/ usr / var / postgres /
Remove pid file

删除pid文件

rm postmaster.pid

rm postmaster.pid
Restart postgress. On Mac,

重新启动postgress。在Mac上，

brew services restart postgresql

brew服务重启postgresql

#10

I resolved the issue via this command

我通过这个命令解决了这个问题

pg_ctl -D /usr/local/var/postgres start

At times, you might get this error

有时，您可能会收到此错误

pg_ctl: another server might be running; trying to start server anyway

So, try running the following command and then run the first command given above.

因此，尝试运行以下命令，然后运行上面给出的第一个命令。

pg_ctl -D /usr/local/var/postgres stop

#1