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