Re: psql - looking in wrong place for socket

Steve Clark <steve.clark@xxxxxxxxxxxxx> · Fri, 17 Mar 2017 09:58:45 -0400

    On 03/17/2017 09:49 AM, Adrian Klaver
      wrote:

      On 03/17/2017 06:42 AM, Steve Clark wrote:

        Hi List,

I am running postgresql 8.4.20 on CentOS 6. Things have been running fine for a long time
then I rebooted. Postgres came up but when I tried to connect with psql on the local machine
I got

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

The socket is actually being created (and always has been) in /tmp

      So you built Postgres from source?

    No - it is installed using yum.

    It looks like the problem is someone loaded postgresql-9.5 and psql
    was using:

    psql    14971 postgres  mem    REG                8,4   193296  
    950807 /usr/pgsql-9.5/lib/libpq.so.5.8

    the libpq from 9.5.

    By removing the ln and using

    # rm /var/run/postgresql/.s.PGSQL.5432 

    rm: remove symbolic link `/var/run/postgresql/.s.PGSQL.5432'? y

    $ psql

    psql: could not connect to server: No such file or directory

            Is the server running locally and accepting

            connections on Unix domain socket
    "/var/run/postgresql/.s.PGSQL.5432"?

    $ LD_LIBRARY_PATH=/usr/lib64 psql

    psql (8.4.20)

    Type "help" for help.

    postgres=#

    It works OK again.

    So now I know what caused the problem.

    Thanks,

    Steve

        I worked around the problem temporarily by
ln -s /tmp/.s.PGSQL.5432 /var/run/postgresql/.s.PGSQL.5432

What controls where psql looks for the socket?

      https://www.postgresql.org/message-id/23876.1488949292%40sss.pgh.pa.us

"With the default configure options you used, the postmaster would have 
put its Unix socket file into /tmp, not /var/run.  I wonder whether your
problem is that you're trying to connect to it with distro-supplied
psql+libpq that expects to find the Unix socket in /var/run."

        Thanks,
Steve

    -- 

      Stephen Clark

      NetWolves Managed Services, LLC.

      Director of Technology

      Phone: 813-579-3200

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      Email: steve.clark@xxxxxxxxxxxxx

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