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Thread: Network Card Not Listening at Startup

Network Card Not Listening at Startup

From
Ludwig Isaac Lim
Date:
Hello:

I'm running postgresql 12.9 on Amazon Linux in AWS. 

My listen_addresses in postgresql.conf is configured like below:
listen_addresses = '172.17.1.57,localhost' 


However, postgresql does not listen on 172..17.1.57. I can reproduce the phenomenon by simply rebooting the server and
thenrun netstat -tulpn 

[root@ip-172-17-1-206 data]#  netstat -tulpn | grep 5432
tcp        0      0 127.0.0.1:5432          0.0.0.0:*               LISTEN      2605/postgres



And there's nothing abnormal in the logs:
2022-02-09 15:59:36.906 UTC [2663] LOG:  database system was shut down at 2022-02-09 15:59:20 UTC
2022-02-09 15:59:36.930 UTC [2605] LOG:  database system is ready to accept connections



I had to run:
systemctl restart postgresql


For 172.17.1.57 to listen

[root@ip-172-17-1-206 data]#  netstat -tulpn | grep 5432
tcp        0      0 127.0.0.1:5432          0.0.0.0:*               LISTEN      4289/postgres
tcp        0      0 172.17.1.57:5432        0.0.0.0:*               LISTEN      4289/postgres


Note that 172.17.1.57 is not the primary network interface. I created the network interface and attached it to the EC2
instance.

My systemd config file for postgresql (/etc/systemd/system/postgresql.service) was copied from 18.3. Starting the
DatabaseServer 





18.3. Starting the Database Server
 18.3. Starting the Database Server 18.3.1. Server Start-up Failures 18.3.2. Client Connection Problems Before an...


Extra information
------------------------------
postgres=# select version();
                                                 version
--------------------------------------------------------------------------------
 PostgreSQL 12.9 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 7.3.1 20180712 (R
(1 row)


How do make sure that NIC will be listening every time I started/restarted the server?

Thanks in advance,
Ludwig Lim

Re: Network Card Not Listening at Startup

From
Tom Lane
Date:
Ludwig Isaac Lim <ludz_lim@yahoo.com> writes:
> How do make sure that NIC will be listening every time I started/restarted the server?

You need to tell systemd not to start the postgresql service
until the network is up.

In basic cases, you can edit the postgresql.service file,
or maybe better create an add-on config file something like this:

$ cat /etc/systemd/system/postgresql.service.d/delay_start.conf
[Unit]
After=network-online.target
Wants=network-online.target

(The add-on file name doesn't matter, the directory name does.)

I'm not certain that this will wait for custom NICs if you are
doing something nonstandard to configure those, but for me
it works for alternate IPs configured in
/etc/sysconfig/network-scripts/ifcfg-whatever.

            regards, tom lane

Re: Network Card Not Listening at Startup

From
Ludwig Isaac Lim
Date:



> On Thursday, February 10, 2022, 01:49:10 AM GMT+8, Tom Lane <tgl@sss.pgh.pa.us> wrote:




>> Ludwig Isaac Lim <ludz_lim@yahoo.com> writes:

>> How do make sure that NIC will be listening every time I started/restarted the server?


> You need to tell systemd not to start the postgresql service
> until the network is up.

> In basic cases, you can edit the postgresql.service file,
> or maybe better create an add-on config file something like this:

> $ cat /etc/systemd/system/postgresql.service.d/delay_start.conf
> [Unit]
> After=network-online.target
> Wants=network-online.target

> (The add-on file name doesn't matter, the directory name does.)

> I'm not certain that this will wait for custom NICs if you are
> doing something nonstandard to configure those, but for me
> it works for alternate IPs configured in
> /etc/sysconfig/network-scripts/ifcfg-whatever.

>            regards, tom lane

Thanks Tom. It works.

Regards,
Ludwig