why socket for communication between master and worker used the so large memory?

[Maxim Dounin]

Hello!

On Fri, Mar 29, 2013 at 06:04:54PM +0800, MCoder wrote:

> my nginx is just a http tunul proxy http connection, and max connection is
> just lower than 100.
> 
> # ps aux
> root     19849  0.0  0.0  18028  2452 ?        Ss    2012   0:00 nginx:
> master process /usr/local/qqwebsrv/nginx/sbin/nginx
> nobody   25389  0.1  0.0  19752  4104 ?        S    Mar25   9:07 nginx:
> worker process
> nobody   25390  0.1  0.0  19752  4104 ?        S    Mar25   9:03 nginx:
> worker process
> nobody   25391  0.1  0.0  19752  4108 ?        S    Mar25   8:46 nginx:
> worker process
> nobody   25392  0.1  0.0  19760  4116 ?        S    Mar25   8:58 nginx:
> worker process
> 
> # lsof | grep nginx | grep socket
> nginx     19849       root    3w     unix 0xffff8102b7574380
>  1677964948 socket

[...]

> nginx     25392     nobody    3u     unix 0xffff8102b7574380
>  1677964948 socket
> nginx     25392     nobody    6u     unix 0xffff8102dce9dcc0
>  1677964950 socket
> nginx     25392     nobody    8u     unix 0xffff81027785a980
>  1677964954 socket
> nginx     25392     nobody   12u     unix 0xffff81010e285100
>  1677964958 socket
> 
> # lsof |awk '$1=="nginx" && $NF == "socket" {n[$6]=$7} END {for (i in n) {m
> += n[i]} print m / (1024 * 1024 * 1024)}'
> 12.5018

What makes you think that what you are counting is memory?  From
here it looks like NODE column, with SIZE/OFF colum omitted for
some reason (likely just empty).  On a linux system here the 
output looks like:

$ lsof | egrep 'socket|SIZE'
COMMAND     PID      USER   FD      TYPE             DEVICE SIZE/OFF    NODE NAME 
nginx     30299   mdounin    3u     unix 0xffff880224f836c0      0t0 1953927 socket
nginx     30299   mdounin    6u     unix 0xffff880413ff0380      0t0 1953928 socket
nginx     30300   mdounin    6u     unix 0xffff880413ff0380      0t0 1953928 socket

-- 
Maxim Dounin
http://nginx.org/en/donation.html