psql could not connect to server Ubuntu – Top 7 reasons and fixes

Databases are essential for internet websites. Any sort of database connection error tends to make customers sick and tired.

A common PostgreSQL connection try benefits in psql could not connect to server Ubuntu error.

This error frequently happens when the psql service is not operating on the server.

Therefore, at Bobcares we normally get requests to repair PostgreSQL connection errors, as a aspect of our Server Management Solutions.

Right now, Let’s have a appear into the psql connection error and see how our Assistance Engineers repair it.


What does the psql connection error indicate?

PostgreSQL is a hugely extensible and handy database management program. And as a result it is 1 of the well-liked database systems.

But several instances, when customers attempt to connect to psql it ends up in connection errors. psql is the interactive terminal-primarily based system, that enables PostgreSQL queries.

The common error message when the psql can not connect to the Ubuntu server shows up as:

Error message sql could not connect to server ubuntu

This error message indicates that the psql service is refusing the connection.


Why psql can not connect to the server?

Generally, psql connection fails, when its service is not operating on the server. There can be several factors for this.

Let’s go over a couple of factors why the psql service fails. We will also go over how our Assistance Engineers repair this error in the Ubuntu server.


1. psql service status

In several scenarios, the database service may perhaps not be operating on the server. As a result when the user is attempting to connect to psql, it ends up in connection error.

When our buyers report this error on Ubuntu, our Assistance Group very first verify for the PostgreSQL service status. For the Ubuntu server, we use 1 amongst the commands.

service postgresql status or ps -ef | grep postgres

If the service is not operating in the server, then we restart it making use of the command.

service postgresql restart

In some scenarios, the service will be corrupted. Then we reinstall it making use of:

apt-get set up package_name


2.Status of Postgres clusters

Even if the psql service is operating, some customers nonetheless may perhaps not in a position to connect to the database. Then the Postgres cluster status may perhaps be down in this scenario.

Generally, clustering assists in redundancy. If 1 server fails the database can perform making use of the other. This tends to make clustering crucial in web-site management.

So, the Assistance Group very first verify for the pg_lsclusters status in the server. If the status is located down, then we restart it making use of

pg_ctlcluster x.x most important commence

Right here x.x denotes the PostgreSQL version quantity.


3. Improper file place

Often, buyers reinstall a new version of Postgres with out uninstalling the older 1. This creates two packages of the exact same service in various areas. This goes unnoticed as the consumer has installed various versions of PostgreSQL.

Due to the fact Ubuntu performs primarily based on a package management program, this can also bring about a connection error.

As a result the Assistance Engineers very first appear for the installed packages in the server. If there is a will need to reinstall the service, we make positive that older files totally removed.


4. No TCP/IP connection

In some instances, the PostgreSQL service will be active and nonetheless the user may perhaps not in a position to connect. Right here the PostgreSQL does not enable TCP/IP connection. To verify the socket connection we use the command.

netstat -pln | grep 5432

5432 is the port that Postgres use for TCP/IP connection.

In this scenario, the Assistance Group makes it possible for TCP/IP connections in the postgresql.conf file.

For Ubuntu server, the configuration file place is /and so on/postgresql/xx/most important/postgresql.conf.


5. Permit remote host

If the customers are not in a position to connect to psql from a remote IP, then also we get the exact same error.

In this case, the Assistance Group edits the postgresql.conf file and enable the IP from which the consumer is attempting to access.

Ultimately, we restart the service to save the adjustments.


6. Ownership of Postgres files

Often the terrible ownership of files can bring about connection errors in PostgreSQL.

In this case, the Assistance Engineers verify the file permissions and ownership.

If it wants any modify, they make the important adjustments making use of the chown command. This can repair the error.


7. Missing Postgres user

A psql connection can also show up when the Postgres user is missing.

For instance, 1 of our buyers removed the Postgres user from the ssl-cert group. To repair the error we had to add the user back into the ssl-cert group.

For that reason, in each and every connection error, we often verify the presence of right Postgres customers.


[Still, having trouble connecting using psql on the Ubuntu server? –; We will fix it for you.]



In brief, the error psql could not connect to the server Ubuntu occurs due to failed PostgreSQL service, missing customers, firewall restrictions and several far more. We saw the best 7 factors for this error and how our Assistance Engineers repair them.

The post psql could not connect to server Ubuntu – Major 7 factors and fixes appeared very first on Bobcares.