netstat showing multiple lines for each listening socket

[Thomas Hungenberg]

On 10.07.24 14:20, Tom Marcoen (EXT) wrote:
> My server has four (virtual; it runs on vSphere) CPUs and also shows four lines in `ss` output.
> 
> The `ps` command shows the `-U` which - I assume - is set automatically triggered by the number of CPUs.
> 
> # ps -elf | grep named
> 5 S named    23769     1  9  80   0 - 251941 do_sig 07:12 ?       00:39:02 /usr/local/sbin/named -U4 -u named -c /usr/local/etc/namedb/named.conf

The manpage says:

        -U #listeners
               This option tells named the number of #listeners worker  threads
               to  listen  on, for incoming UDP packets on each address. If not
               specified, named calculates a default value based on the  number
               of  detected  CPUs: 1 for 1 CPU, and the number of detected CPUs
               minus one for machines with more than 1 CPU.


So if not specified, the value of "-U" should be set to 3 with four CPUs.
Also, the parameter "-U" usually does not show up in the ps output if not specified.

So in your case it looks more like named is specifically started with "-U4"?


     - Thomas