Postgres could not connect to Server

Before you came to this problem, I assume you backup your Postgres database already.

Recently I upgraded my Mac OS X 10.9 (Mavericks) to Mac OS X 10.10 (Yosemite). All is installations  process on new OS is working perfectly fine, and a lot for features on 10.10 is new to the dependencies of my previews web apps. WhenI tried to run one of my web-apps that was working previously on 10.9, it cannot connect the Posgtres DB to the Web App server. The errors goes like this

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


Then I tried to google around and found some answers which I tried to apply on my terminal.

One thing I tried was to make directory and check.

brew uninstall postgres
brew install postgres
sudo mkdir /var/pgsql_socket/
sudo ln -s /private/tmp/.s.PGSQL.5432 /var/psql_socket/
rm /usr/local/var/postgres/postmaster.pid
pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start

Try running postgres -D /usr/local/var/postgres — it will give you a much more verbose output if postgres fails to start.

In my case, running rm -rf /usr/local/var/postgres && initdb /usr/local/var/postgres -E utf8removed my old databases and then reinitialized the postgres db schema.

Check that the socket file exists.

Andre$ ls -l /tmp/.s.PGSQL.5432
srwxrwxrwx  1 tech3  wheel  0 Feb 23 16:26 /tmp/.s.PGSQL.5432

Andre$ grep unix_socket /usr/local/var/postgres/postgresql.conf
#unix_socket_directories = '/tmp' # comma-separated list of directories
#unix_socket_group = '' # (change requires restart)
#unix_socket_permissions = 0777 # begin with 0 to use octal notation

Then another thing was to unload plist file, remove pid and load back plist file.

launchctl unload ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist
rm /usr/local/var/postgres/postmaster.pid
launchctl load ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist

Additionally you have to check if you have the latest XCode ver 6.1.1 on your machine and also Command Line Tools for OS X 10.10 (Yosemite). Please refer to the link below – ciao!

https://developer.apple.com/downloads/index.action#