Socket File "/var/pgsql_socket/.s.PGSQL.5432" Missing In Mountain Lion (OS X Server)

Question

I just upgraded my MacMini Server from Lion Server to Mountain Lion using OS X Server. I am having the same problem with PostgreSQL that I did last year when I first installed Lion Server.

When I try to do any kind of PostgreSQL terminal command I get the following notorious error message that many have gotten over the years:

psql: could not connect to server: No such file or directory
    Is the server running locally and accepting
    connections on Unix domain socket "/var/pgsql_socket/.s.PGSQL.5432"?

I was attempting to change the password for _postgres when I got the error. I tried several commands but got the same error. I just rebooted my server but no luck. I logged in as root to look at /var/pgsql_socket and the folder is empty. Folder /var/pgsql_socket_alt is also empty.

I have checked online about this. However just about all of the solutions I have read, including on Stack Overflow, suggest a removal and reinstall of PostgreSQL. I do not know but this does not seem like a plausible option because several options on the Server App use PostgreSQL. I contacted Apple Enterprise Support (no agreement) and I was told that my issue would have to be solved by the developers which would cost $695.

I have a website that is down right now because I cannot rebuild it. I don't know where to turn for help with this at this point. I will continue looking online to see if I can find something. However I hope that someone can give me an answer quick so I can rebuild my database.

Update: 12/13/2012 15:33 GMT-6

Here is my output for ps auwx|grep postg:

_postgres      28123   0.0  0.1  2479696   7724   ??  Ss    3:01PM   0:00.04 /Applications/Server.app/Contents/ServerRoot/usr/bin/postgres_real -D /Library/Server/PostgreSQL For Server Services/Data -c listen_addresses= -c log_connections=on -c log_directory=/Library/Logs/PostgreSQL -c log_filename=PostgreSQL_Server_Services.log -c log_line_prefix=%t  -c log_lock_waits=on -c log_statement=ddl -c logging_collector=on -c unix_socket_directory=/Library/Server/PostgreSQL For Server Services/Socket -c unix_socket_group=_postgres -c unix_socket_permissions=0770
server1        28216   0.0  0.0  2432768    620 s000  R+    3:02PM   0:00.00 grep postg
_postgres      28138   0.0  0.0  2439388    752   ??  Ss    3:01PM   0:00.01 postgres: stats collector process                           
_postgres      28137   0.0  0.0  2479828   1968   ??  Ss    3:01PM   0:00.00 postgres: autovacuum launcher process                           
_postgres      28136   0.0  0.0  2479696    544   ??  Ss    3:01PM   0:00.00 postgres: wal writer process                           
_postgres      28135   0.0  0.0  2479696    732   ??  Ss    3:01PM   0:00.01 postgres: writer process                           
_postgres      28134   0.0  0.0  2479696    592   ??  Ss    3:01PM   0:00.00 postgres: checkpointer process                           
_postgres      28131   0.0  0.0  2439388    368   ??  Ss    3:01PM   0:00.00 postgres: logger process 

Update: 12/13/2012 18:10 GMT-6

After intense web searching this video was found. I was able to get PostgreSQL working and remove the error. I am able to connect using pgadmin and phppgadmin. I was about to go back to Lion Server because of sheer frustration. Now I will not have to.

http://www.youtube.com/watch?v=y1c7WFMMkZ4

Percipient

Your issue boils down to the fact that the Mac OS X pre-installed version of PostgreSQL's psql is on your PATH before the version you installed. They look for the unix socket in different places. Either use tcp/ip by specifying -h localhost or preferably fix your PATH so the correct psql is found first. Apple's bizarre decision to not only bundle PostgreSQL, but mess with it so it put things in non-standard places is the root cause of this problem. – Eliseelisee

There is an ongoing issue in OSX, where the packagers decided to put the unix-domain socket at a different place than normal. Let me search ... BRB ... https://mcmap.net/q/48936/-can-not-connect-to-local-postgresql – Fondle

I copied an old PATH in .bashrc. I have not installed another version of postgreSQL. Here is my PATH statement which includes code for RVM. If someone could tell me what to change it to I will do that. When I do which psql it is found in /usr/bin/psql. Thanks so much for all of you for your help. PATH="$PATH:$HOME/.rvm/bin:/usr/bin/psql:/usr/local:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin" I am also searching for the socket file while logged in as root. – Percipient

For those using homebrew and osx @CraigRinger might have the right answer for you, confirm with brew doctor. – Savonarola

Answer 1

I was able to add the following to my .bash_profile to prevent the error:

export PGHOST=localhost

This works because:

If you omit the host name, psql will connect via a Unix-domain socket to a server on the local host, or via TCP/IP to localhost on machines that don't have Unix-domain sockets.

Your OS supports Unix domain sockets, but PostgreSQL's Unix socket that psql needs either doesn't exist or is in a different location than it expects.

Specifying a hostname explicitly as localhost forces psql to use TCP/IP. Setting an environment variable PGHOST is one of the ways to achieve that. It's documented in psql's manual.

Alvin

For anyone running into this with a Rails app: you can specify the host in database.yml. – Ferricyanide

What kind of sorcery is this? I mean, seriously. Could you explain? – Wilhelminawilhelmine

in fish shell set -x PGHOST $PGHOST "localhost" – Pie

I always come back to this answer! Saved my life again. This snippet really belongs on this page, postgresapp.com/documentation/cli-tools.html. – Burgee

I don't why, but it works for me! I met this problem in rails 5 when I use 'rails db:create', but I have already set the host: localhost in database.yml. @Ferricyanide – Dinnerware

It worked for me, but I don't know how. Would love to get some explanations? – Lynnalynne

This worked for Rails 5.2 without modifying database.yml, when this error appeared after downgrading Postgres to an older Homebrew-managed version. – Sodamide

it's 2020 and after upgrading Postgres.app, I ran into "No such file or directory: /var/pgsql_socket/.s.PGSQL.5432". After hours I found this which solved it. None of all the complicated solutions achieved anything but messing up Terminal.. – Captor

Answer 2

Try paste in console this:

$ mkdir /var/pgsql_socket/ 

$ ln -s /private/tmp/.s.PGSQL.5432 /var/pgsql_socket/

Piquet

Finally, I got this answer. – Kafka

Good. Even though I think I know why this is working, a little more explanation would be useful. This solution is better than the accepted answer, only the details are missing. – Dehiscent

@Dehiscent MacOS has a non-standard location for the sockets. The answerer is creating a new folder for the expected and standard location and then linking then non-standard postgres unix socket location (/private/tmp/.s.PGSQL.5432) to the standard location (/var/pgsql_socket/) . Notice that you may need sudo – Overcapitalize

I can confirm, that this worked for me after trying a lot of other things :) – Remittee

Answer 3

I was able to solve by simply filling in 127.0.0.1 for the PostgreSQL host address rather than leaving it blank. (Django Example)

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'database_name',
        'USER': 'database_user',
        'PASSWORD': 'pass',
        'HOST': '127.0.0.1',
        'PORT': '',
        }
}

Cepheus

I feel kind of dumb now, I've been trying to fix this issue for about 2 days. On Windows I was using '127.0.0.1', but then I moved my code to production (Debian 7) and had to change it to ''. It is kind of weird that they give such an error message that leads one to believe that the problem might be somewhere else. – Paff

Answer 4

Open 'postgresql.conf' in you favourite editor. Look for the variable 'unix_socket_directories', it will most likely look like this:

unix_socket_directories = '/private/tmp/'

Change the line to this:

unix_socket_directories = '/var/pgsql_socket/'

Note if you want the socket files in more than one directory comma separate them.

Fie

This had the desired effect of trying to create the socket elsewhere, but the server wouldn't start because it didn't have the permissions to create files in the /var directory. I ended up changing configuration files at a higher level to simply use the socket where it was originally. Pretty much as given in this answer https://mcmap.net/q/49615/-socket-file-quot-var-pgsql_socket-s-pgsql-5432-quot-missing-in-mountain-lion-os-x-server. – Ladybug

Answer 5

A much more simple solution (thanks to http://daniel.fone.net.nz/blog/2014/12/01/fixing-connection-errors-after-upgrading-postgres/) . I had upgraded to postgres 9.4. In my case, all I needed to do (after a day of googling and not succeeding)

gem uninstall pg
gem uninstall activerecord-postgresql-adapter
bundle install

Restart webrick, and done!

Sinhalese

Answer 6

As mentioned by others in the comments, a really simple solution to this issue is to declare the database 'host' within the database configuration. Adding this answer just to make it a little more clear for anyone reading this.

In a Ruby on Rails app for example, edit /config/database.yml:

development:
  adapter: postgresql
  encoding: unicode
  database: database_name
  pool: 5
  host: localhost

Note: the last line added to specify the host. Prior to updating to Yosemite I never needed to specify the host in this way.

Hope this helps someone.

Cheers

Realtor

I needed to set my host to the directory that I found contained the .s.PGSQL.5432 file. – Ladybug

Answer 7

Check for the status of the database:

service postgresql status

If the database is not running, start the db:

sudo service postgresql start

Ulster

stuck with the above error and resolved it by starting the db. – Ulster

Answer 8

Can you check your postgresql.conf file ??

On what port your postgres is running ??

I think it is not running on port 5432.If not change it to 5432

OR on terminal use

psql -U  postgres -p YOUR_PORT_NUMBER database_name

Vidal

I cannot run the terminal command. I get the same error. I need help on where I could find the postgresql.conf file. I used to have a /var/pgsql folder when running Lion Server. I guess that is gone now. I have just posted my output for the ps grep command. I turned on the Wiki service in order to run PostgreSQL. I was told that I could use the sudo serveradmin commands without turning on any Server app services but they do not work. I am logged in as root right now so I should be able to do anything :) I checked ports in Network Utility. 5432 not used. – Percipient

Answer 9

I had this problem with Django.

Fix it by explicitly setting your hostname to "localhost".

Leake

Answer 10

i make in word by doing this:

dpkg-reconfigure locales

and choose your preferred locales

pg_createcluster 9.5 main --start

(9.5 is my version of postgresql)

/etc/init.d/postgresql start

and then it word!

sudo su - postgres
psql

Horgan

Answer 11

For RubyOnRails app add localhost If you use custom Postgresql version

# config/database.yml
default: &default
  host: localhost

Agonic

This is a solution to move from unix socket to network socket. A better solution would be to recompile postrgres gem pg to match the changes on postrgesql due to upgrade or whatever change: gep pristine pg – Matins

Answer 12

File permissions are restrictive on the Postgres db owned by the Mac OS. These permissions are reset after reboot, or restart of Postgres: e.g. serveradmin start postgres.

So, temporarily reset the permissions or ownership:

sudo chmod o+rwx /var/pgsql_socket/.s.PGSQL.5432
sudo chown "webUser"  /var/pgsql_socket/.s.PGSQL.5432

Permissions resetting is not secure, so install a version of the db that you own for a solution.

Dissertate

Answer 13

If you have the above problem but you have upgraded from Yosemite, then a different approach is needed as the upgrade solution can destroy some files. More details are at `pg_tblspc` missing after installation of latest version of OS X (Yosemite or El Capitan).

Durden

Answer 14

apt-get install postgres-xc-client
apt-get install postgres-xc

Kandacekandahar

Answer 15

First remove the installed postgres:

sudo apt-get purge postgr*
sudo apt-get autoremove

Then install 'synaptic':

sudo apt-get install synaptic
sudo apt-get update

Then install Postgres

sudo apt-get install postgresql postgresql-contrib

Sakai

Answer 16

psql: could not connect to server: No such file or directory
    Is the server running locally and accepting
    connections on Unix domain socket"/var/pgsql_socket/.s.PGSQL.5432"?

I kept on getting the above error and none of the above solutions worked for me. Finally the following solution solved my problem on Mac OS X

Install postgres using brew

brew install postgres

Install brew services

brew tap homebrew/services

To start postgres as a background service

brew services start postgresql

To stop postgres manually

brew services stop postgresql

We can also use brew services to restart Postgres

brew services restart postgresql

Cockatoo

Answer 17

check the postgres server is running with following code

sudo service postgresql status

if the postgres server is inactive, write the following command.

sudo service postgresql start

Edythedythe

Answer 18

I got this error after my computer froze and rebooted on its own. The solution for me was not found on this page, rather on another very highly rated SO question with the same error psql: could not connect to server: No such file or directory (Mac OS X). The answer: just delete this file /usr/local/var/postgres/postmaster.pid, then brew services restart postgresql did the trick. Heed the warning on the linked answer about killing postgres processes before doing this else you could corrupt your db permanently.

Luna

Answer 19

It took me a while but I was able to get this working finally after going through the suggestions offered and additional web searches being done. I used the information in the following YouTube video created by Mactasia:

http://www.youtube.com/watch?v=y1c7WFMMkZ4

When I did this I saw the file with .lock as the extension. However I still got the error when I tried to start the Rails Server when I resumed working on my Rails application using PostgreSQL. This time I got a permission denied error. This is when I remembered that not only did I have to change listen_addresses in the plist but I also had to change unit_socket_permissions to 0777. I also logged in as root to change the permissions on the var/pgsql_socket folder where I could access it at the user level. Postgres is working fine now. I am in the process of reloading my data from my SQL backup.

What I did not understand was that when I had wiki turned on PostgreSQL was supposedly working when I did a sudo serveradmin fullstatus postgres but I still got the error. Oh well.

Percipient

Answer 20

I just created a new cluster and that worked for me, I was using (PostgreSQL) 9.3.20:

sudo pg_createcluster 9.3 main --start

Antipyretic