PostgresSQL is not getting connected - postgresql

I am new to Ubuntu operating system and trying to install postgresSQL in my system.
After completing the installation and entering postgres mode when I enter the command pgsql, it gives me this error
psql: error: 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"?
what could possibly be wrong??

Probably the postgresql server is not running; you can run netstat -adp to see if postgres is listening on port 5432.
If it isn't, then it most likely isn't running; systemctl status postgresql will help identify if it is even installed, and if it has run into any issues (for further details, see https://mydbanotebook.org/post/troubleshooting-01/)
If it is running and seems healthy, then it might not be configured to accept connections in whichever way you are connecting (which user, database, host/network etc) - see details about the pg_hba.conf file that includes rules for this - https://www.postgresql.org/docs/9.1/auth-pg-hba-conf.html

After install, you must create an instance with initdb.
Later, change the listen_address to *, restart the service and now you can check the port.
Check the pg log for the message: "postgres is ready to accept connections"

Related

postgreSQL server not loading

I'm trying to install postgreSQL(11) server on my local machine.I have downloaded PgAdmin 4(Mac) from the official website and installed it.
When I open the pgadmin the server is opening on random ports like 55957,55062 etc, not on 5432.
I have edited my "PostgreSQL.conf" and changed the listen address=* and port =5432 ,but I could not able to restart the service.
When I type "sudo service postgreSQL restart" it was showing "Sudo : Service command not found"
Also "Sudo command not found".
I don't have much experience in installing postgreSQL ,Can anyone please let me know what I'm doing wrong and let me know how I can add the server in postgres.
Note: I have opened pgadmin - select add new server - localhost as server name and User and DB as postgres.But when I put 5432 as port it was giving the common error "Whether TCP/ip accepting on 5432" and when I put the port where the pgadmin server is currently running (127.0.0.1:55097) it was getting timed out exception.

Cannot connect PostgreSQL with psql - wrong UNIX-Domain-Socket

I'm running CentOS 7.5 and cannot setup PostgreSQL.
If I'm logged in as user postgres and type psql postgres I get the following error message:
psql: Could not connect to server: no such file or directory
does the server run locally and accepts connections on Unix-Domain-Socket "/var/run/postgresql/.s.PGSQL.5432"
However, I changed the port to 5543 (did so in etc/systemd/system/postgresql.service by including /lib/systemd/system/postgresql.service as a [Service] and setting Environment=PGPORT=5543). Note that you shouldn't change it directly in /lib/ because that will get overwritten.
So, the server looks for the wrong UNIX-Domain-Socket and does not find one (because it does not exist), but the socket for the correct port 5543 does exist according to sudo netstat -nlp:
5486/postgres /var/run/postgresql/.s.PGSQL.5543
postgresql.service is running according to systemctl status postgresql.service
Any constructive help is appreciated.
Why are you changing it in systemd and not using PostgreSQL's config file? Is that a CentOS thing?
Anyway - you can run the server on any port you like, or run multiple server instances of the same or different versions on a variety of ports. In that case though you need to tell psql what port to use.
You can set an environment variable (PGPORT), specify it with -p on the command-line or in a .psqlrc file. See the manuals for details.
Edit in response to comments:
If you want to set the PGPORT for psql, do it in the user's shell defaults or in /etc/bash... or equivalent. You could of course replace psql with an alias using your custom port or recompile the binary itself if you wanted.
I'm not sure this is really much use from a security perspective. It seems unlikely that someone can run local processes on your machine, has gained access to your postgres user password but isn't smart enough to see what port the server is running on.

Postgres service started, but can't connect. Nothing listening on port 5432

I don't know how this happened, but my postgres server (9.6.2) has stopped working locally. I seem to be able to start it up, and stop it using:
brew services start postgresql and brew services start postgresql but when I try to connect using psql I get this error:
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"?
When I try to see if anything is listening on port 5432 using lsof -i :5432 I get nothing.
Looked at other posts that say check the pg_hba.conf file, which I did, but doesn't seem to be the problem.
I ended up reinstalling postgres via homebrew. That by itself didn't do enough. I had to kill my data directory to get this to work (i.e. rm -rf /path/to/my/data/directory) and then rebuild it using initdb.
This solution obviously only works if you don't care about keeping your data (in my case, it was just data for my dev environment, so I didn't). If you do want to save a copy of your data, I you'd have to come up with something else.

Postgresql installation

I'm going crazy with postgresql (9.1) installation on my server (debian) i have rent on gandi.net !
I did the aptitude get-install postgresql postgresql-client command.
I'm having this error when trying to execute psql command.
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"?
I've been searching on the web. And maybe the servers are not running. I don't know how to check and how to launch them.
My postgres command doesn't work either (command not found).
Any idea?
The database engine is not running.
service postgresql start
or
/etc/init.d/postgresql start
to start the engine. I don't remember though if debian initializes the data dir automatically.

pgAdmin and PostgreSQL: can't connect to server

I just installed PostgreSQL on Snow Leopard and can't connect to the database server via pgAdmin 3.
I'm on my local machine, however I keep getting this 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 5423?
I'm a bit of a noob when it comes to Postgres, so I'm not really sure what the problem is.
I can, however, log in through the command line, via psql -U postgres, and start and stop the server successfully.
Any help would be much appreciated.
The error message pointed out that you tried to connect to server on port 5423. However, postgres server listens on 5432 by default.
From your above comment (SHOW port; gives me "5432"), I think you need to change the port to 5432!
UPDATE: Tuan Dang spotted it. I'll leave this answer in place in case it helps someone else for whom the issue isn't quite the same.
Since you can connect via the command line, run:
SHOW port;
from psql. You'll probably see that the port is not 5432. You need to connect to the port PostgreSQL is actually running on from your application.
It's also possible that it just isn't listening on TCP/IP. Run:
SHOW listen_addresses;
to see what it's listening for.
The reason you can connect via the command line is likely to be because the command line psql you're using is connecting over a unix socket (since you didn't specify a host) and your app is connecting via tcp/ip.