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Date: Mon, 22 Apr 2024 14:59:39 -0700
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Subject: Re: issue with reading hostname
To: Atul Kumar <akumar14871@gmail.com>
Cc: pgsql-general <pgsql-general@postgresql.org>
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From: Adrian Klaver <adrian.klaver@aklaver.com>
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On 4/22/24 14:54, Atul Kumar wrote:
> I mean, Once I change the hostname then how will the socket read the new 
> hostname ? Does it require a postgres service restart ?

The host name of the machine?

> 
> 
> 
> On Tue, Apr 23, 2024 at 3:19 AM Adrian Klaver <adrian.klaver@aklaver.com 
> <mailto:adrian.klaver@aklaver.com>> wrote:
> 
>     On 4/22/24 14:37, Atul Kumar wrote:
>      > Can we edit the socket to change the hostname in it ?
> 
>     On Ubuntu 22.04 install, given:
> 
>     srwxrwxrwx  1 postgres postgres    0 Apr 22 14:01 .s.PGSQL.5432=
>     -rw-------  1 postgres postgres   68 Apr 22 14:01 .s.PGSQL.5432.lock
> 
>     The contents of .s.PGSQL.5432.lock(the file that indicates a Postgres
>     instance has a lock on the socket) are:
> 
>     862
>     /var/lib/postgresql/15/main
>     1713795311
>     5432
>     /var/run/postgresql
> 
>     There is no hostname to be changed as you are working with a local
>     socket.
> 
>      >
>      > Regards.
>      >
>      > On Tue, Apr 23, 2024 at 2:41 AM Ron Johnson
>     <ronljohnsonjr@gmail.com <mailto:ronljohnsonjr@gmail.com>
>      > <mailto:ronljohnsonjr@gmail.com
>     <mailto:ronljohnsonjr@gmail.com>>> wrote:
>      >
>      >     On Mon, Apr 22, 2024 at 4:14 PM Atul Kumar
>     <akumar14871@gmail.com <mailto:akumar14871@gmail.com>
>      >     <mailto:akumar14871@gmail.com
>     <mailto:akumar14871@gmail.com>>> wrote:
>      >
>      >         Hi,
>      >
>      >         I have postgresql  version 15 running on centos7.
>      >
>      >         I have below query that reads hostname from /tmp directory:
>      >
>      >         psql postgres -A -t -p 5432 -h /tmp/ -c 'SELECT
>      >         pg_is_in_recovery();'
>      >
>      >
>      >     If you installed from the PGDG repository (possibly also the
>     CENTOS
>      >     repos, but I'm not sure), then the domain socket also lives in :
>      >     /var/run/postgresql
>      >
>      >     * I find that more expressive than /tmp.
>      >     * No need to specify the host when using sockets.
>      >     * Using a socket name makes parameterizing the hostname easier in
>      >     scripts.
>      >
>      >
> 
>     -- 
>     Adrian Klaver
>     adrian.klaver@aklaver.com <mailto:adrian.klaver@aklaver.com>
> 

-- 
Adrian Klaver
adrian.klaver@aklaver.com