PostgreSQL error Could not connect to server No such file or directory

Question

Like some others I am getting this error when I run rake db migrate in my project or even try most database tasks for my Ruby on Rails 3 2 applications      PGError  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     I installed PostgreSQL with Homebrew a long time ago and following an attempted installation of MongoDB recently my PostgreSQL install has never been the same  I m running OS nbsp X nbsp v10 6 Snow nbsp Leopard   What s wrong and how do I better understand how PostgreSQL is and should be setup on my Mac   So far  I think  this tells me that PostgreSQL is not running      ps -aef grep postgres                                                                                                    ruby-1 9 2-p320 jct-ana   develop      501 17604 11329   0   0 00 00 ttys001    0 00 00 grep postgres   But does this tell me that PostgreSQL is running     launchctl load -w  usr local Cellar postgresql 9 1 4 homebrew mxcl postgresql plist                                                         ruby-1 9 2-p136   homebrew mxcl postgresql  Already loaded   How do I fix this  what am I not seeing   PS    Library LaunchAgents includes two PostgreSQL  plist files  I am not sure if that s relevant   org postgresql postgres plist homebrew mxcl postgresql plist   I tried the following and got a result as below     psql -p 5432 -h localhost     psql  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  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   fe80  1  and accepting     TCP IP connections on port 5432    I ve read since that this is occuring because OS nbsp X installs its own version of PostgreSQL and Homebrew installs a different version in a different place and the PostgreSQL commands are looking in the  tmp  directory  You ll need to search more on Stack nbsp Overflow  but basically you symlink PostgreSQL so that anything looking in that tmp path actually finds the real path  if that makes sense   This is the link where I found a few more things to try  specifically doing the symlink as per above  Mac OSX Lion Postgres does not accept connections on  tmp  s PGSQL 5432  I still wish someone would put together a decent explanation of the concepts behind installing PostgreSQL on OS nbsp X and why it s all so difficult   Latest insights to help with troubleshooting     which psql    This tells you which PostgreSQL you are using when you run   psql     Then run     echo  PATH   The key thing to take into account is this   Ensure that the path entry for the copy of PostgreSQL you want to run COMES BEFORE the path to the OS nbsp X system s PostgreSQL   This is a core requirement which decides which PostgreSQL gets run and is what I m told leads to most of these issues

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For me  this works  rm  usr local var postgres postmaster pid

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There might be different issues with running PostgreSQL locally  I would recommend to clean all versions of postgres installed and start fresh  Once you have it installed  it s very easy to recreate your database if you have your rails project with the up to date db schema rb  Here is how I usually install PostgreSQL on a Mac  If you re running your database under the root user locally  you might want to omit the last step that creates a todo user

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If you re on MacOS and using homebrew I found this answer extremely helpful    https   stackoverflow com a 27708774 4062901  For me  my server was running but because of an upgrade I was having issues connecting  note  I use brew services   If Postgres is running  try cat  usr local var postgres server log and see what the logs say  My error was a migration  not a connection issue   Also after the manual migration they propose  which does work but  I found there was no longer a table for my user  Try this command to fix that  createdb  answered via psql  FATAL  database  quot  lt user gt  quot  does not exist

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It s very simple  Only add host in your database yaml file

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for what it s worth  I experienced this same error when I had a typo  md4 instead of md5  in my pg hba conf file   etc postgresql 9 5 main pg hba conf   If you got here as I did  double-check that file once to make sure there isn t anything ridiculous in there

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I had PostgreSQL 9 3 and got the same error      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 fixed this using   chmod 777   var lib pgsql 9 3 data pg hba conf  service postgresql-9 3 restart   It works for me

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I fixed this by upgrading postgres   brew update brew upgrade   Then I had to also upgrade the databases to be compatible with the new major version  because I upgraded from 10 to 11   brew postgresql-upgrade-database    source https   github com facebook react-native issues 18760 issuecomment-410533581

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I don t really know Mac or Homebrew  but I know PostgreSQL very well   You want to figure out where the logs are from PostgreSQL trying to start and what the socket directory is for PostgreSQL   By default when you build PG  the socket directory is  tmp    If you didn t change that when you built PG and then you started PG  you should be able to see a socket file in  tmp if you do  ls -al  tmp  The socket file starts with a      so you won t see it with the  -a  to ls   If you don t see a socket there  and you don t see anything from ps awux   grep postgres  then PG is probably not running  or maybe it is and it s the OSX-installed one   What might be happening is that you might be getting a conflict on listening on port 5432 on localhost- use netstat -anp to see what  if anything  is listening on 5432   If a Mac OSX PG is already listening on that port then that might be the problem   Hope that helps   I have heard that homebrew can make things a bit ugly and a lot of people I ve talked to encourage using a VM instead

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quot Postgres app quot  is a better fix if you are on OS X  Here is the fix   Stop the database cd  var sudo rm -r pgsql socket sudo ln -s  tmp pgsql socket chown  postgres  postgres pgsql socket Restart PostgreSQL  not your computer   More information is available at  quot postgresql 9 0 3  on Lion Dev Preview 1 quot

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If you are running Homebrew  uninstall Postgresql end pg gems      gem uninstall pg   brew uninstall postgresql   Download and run the following script to fix permission on  usr local   https   gist github com rpavlik 768518    ruby fix homebrew rb   Then install Postgres again and pg gem      brew install postgresql     initdb  usr local var postgres -E utf8   To have launchd start postgresql at login run      ln -sfv  usr local opt postgresql   plist   Library LaunchAgents    Or start manually   Install pg gem     gem install pg   I hope have helped

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One of the reason could be that   unix socket directories in postgresql conf file is not listed with the directory it is looking for   In the question example it is looking for directory  tmp this has to be provided in the postgresql conf file  something like this    unix socket directories     var run postgresql  tmp       comma-separated list of directories   This solution worked for me

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I encountered this error when running on Mac 10 15 5 using homebrew and seems to be a more updated solution that works where the ones above did not  There is a file called postmaster pid which should is automatically deleted when postresql exits  If it doesn t do the following  brew services stop postgresql  lt --- Failing to exit before rm could corrupt db sudo rm  usr local var postgres postmaster pid

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One reason you get this error is that your local postgres database shuts down when you restart your computer   In a new terminal window  simply type     psql -h localhost    to restart the server

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When you run  psql -p 5432 -h localhost it does not use the loopback driver but uses a real socket and hence you need to configure postgres to accept socket connections  Hence even though pgadmin and other clients may work  psql will not   You need to change both the postgresql conf file and the pg hba conf files so allow connection over a real socket  This will also allow connection from a remote ip which is why it is disabled by default   These files are in the data directory but the actual location can be different depending on how postgres was installed  With postgres running  run the command   ps -ef   grep postmaster   These two files are the -D directory  maybe  usr local pgsql data    For the postgresql conf file  uncomment the listen address and change it to be   listen address         For the pg hba conf add the line   host all all 0 0 0 0 0 md5

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Just restart Postgres as soon as error appears by running brew services restart postgresql and then try again

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Check there is no postmaster pid in your postgres directory  probably  usr local var postgres    remove this and start server   Check - https   github com mperham lunchy is a great wrapper for launchctl

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Hello world   The best but strange way for me was to do next things  1  Download postgres93 app or other version  Add this app into  Applications  folder   2  Add a row  command  into the file  bash profile  which is in my home directory     export PATH  Applications Postgres93 app Contents MacOS bin   PATH It s a PATH to psql from Postgres93 app  The row  command  runs every time console is started   3  Launch Postgres93 app from  Applications  folder  It starts a local server  port is  5432  and host is  localhost     4  After all of this manipulations I was glad to run   createuser -SRDP user name and other commands and to see that it worked  Postgres93 app can be made to run every time your system starts   5  Also if you wanna see your databases graphically you should install PG Commander app  It s good way to see your postgres DB as pretty data-tables  Of  course  it s helpful only for local server  I will be glad if this instructions help others who has faced with this problem

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So for a lot of the issues here  it seems that people were already running psql and had to remove postmaster pid  However  I did not have that issue as I never even had postgres installed in my system properly   Here s a solution that worked for me in MAC OSX Yosemite    I went to http   postgresapp com  and downloaded the app  I moved the app to Application  directory I added it to  PATH by adding this to  bashrc or  bash profile or  zshrc   export PATH  PATH  Applications Postgres app Contents Versions latest bin I ran the postgres from the Applications directory and ran the command again and it worked    Hope this helps  Toodles   Also  this answer helped me the most  https   stackoverflow com a 21503349 3173748

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I had that problem when I upgraded Postgres to 9 3 x  The quick fix for me was to downgrade to whichever 9 2 x version I had before  no need to install a new one      ls  usr local Cellar postgresql  9 2 4 9 3 2   brew switch postgresql 9 2 4   launchctl unload   Library LaunchAgents homebrew mxcl postgresql plist   launchctl load   Library LaunchAgents homebrew mxcl postgresql plist  lt open a new Terminal tab or window to reload gt    psql    Homebrew install specific version of formula   offers a much more comprehensive explanation along with alternative ways to fix the problem

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This worked for me for the error you mentioned  Do one of these    Possibly change your default port specified in the postgres conf file  if you have used something other than the default port  5432 while installing   Change the port number in postgresql conf and restart the DB server  Instead of psql type the full command   psql -p 5432 -h localhost       server name and the port no

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The Cause  Lion comes with a version of postgres already installed and uses those binaries by default  In general you can get around this by using the full path to the homebrew postgres binaries but there may be still issues with other programs   The Solution     curl http   nextmarvel net blog downloads fixBrewLionPostgres sh   sh   Via   http   nextmarvel net blog 2011 09 brew-install-postgresql-on-os-x-lion

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for me command rm  usr local var postgres postmaster pid didn t work cause I installed a specific version of postgresql with homebrew   the right command is rm  usr local var postgres 10 postmaster pid   then brew services restart postgresql 10

[postgresql] PostgreSQL error 'Could not connect to server: No such file or directory'

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