Nginx and multiple cpu

Server NGINX
1

Hi,

I have a 8 core (4 core and HT enabled) machine to test nginx. In my
configuration file

worker_processes 8;

events {
worker_connections 30000;
}

I have done a simple test on that 4 core here is mpstat -P ALL 1 output

05:08:35 PM CPU %user %nice %sys %iowait %irq %soft
%steal %idle intr/s
05:08:36 PM all 4.12 0.00 7.62 2.12 0.25 6.99
0.00 78.90 12902.00
05:08:36 PM 0 19.00 0.00 17.00 0.00 0.00 1.00
0.00 63.00 1001.00
05:08:36 PM 1 1.00 0.00 2.00 0.00 0.00 0.00
0.00 97.00 0.00
05:08:36 PM 2 1.00 0.00 4.00 6.00 0.00 0.00
0.00 89.00 25.00
05:08:36 PM 3 1.00 0.00 1.00 0.00 0.00 0.00
0.00 98.00 0.00
05:08:36 PM 4 7.92 0.00 23.76 0.00 0.00 1.98
0.00 66.34 0.00
05:08:36 PM 5 0.00 0.00 3.03 0.00 0.00 0.00
0.00 96.97 1.00
05:08:36 PM 6 0.99 0.00 2.97 9.90 0.00 0.00
0.00 86.14 0.00
05:08:36 PM 7 2.02 0.00 7.07 0.00 2.02 52.53
0.00 36.36 11875.00

05:08:36 PM CPU %user %nice %sys %iowait %irq %soft
%steal %idle intr/s
05:08:37 PM all 1.75 0.00 5.24 1.00 0.12 6.74
0.00 85.14 9524.24
05:08:37 PM 0 0.00 0.00 0.00 0.00 0.00 0.00
0.00 100.00 1011.11
05:08:37 PM 1 0.00 0.00 0.00 0.00 0.00 0.00
0.00 100.00 0.00
05:08:37 PM 2 0.00 0.00 0.00 0.00 0.00 0.00
0.00 100.00 7.07
05:08:37 PM 3 2.97 0.00 7.92 0.00 0.00 0.00
0.00 89.11 0.00
05:08:37 PM 4 0.00 0.00 0.00 0.00 0.00 0.00
0.00 100.00 0.00
05:08:37 PM 5 0.00 0.00 0.00 0.00 0.00 0.00
0.00 100.00 0.00
05:08:37 PM 6 0.00 0.00 5.00 9.00 0.00 0.00
0.00 86.00 0.00
05:08:37 PM 7 10.89 0.00 28.71 0.00 0.99 53.47
0.00 5.94 8504.04

05:08:37 PM CPU %user %nice %sys %iowait %irq %soft
%steal %idle intr/s
05:08:38 PM all 2.75 0.00 5.25 0.00 0.12 7.00
0.00 84.88 8087.13
05:08:38 PM 0 8.91 0.00 10.89 0.00 0.00 0.99
0.00 79.21 991.09
05:08:38 PM 1 0.00 0.00 0.00 0.00 0.00 0.00
0.00 100.00 0.00
05:08:38 PM 2 0.00 0.00 2.00 0.00 0.00 0.00
0.00 98.00 0.00
05:08:38 PM 3 3.00 0.00 7.00 0.00 0.00 0.00
0.00 90.00 0.00
05:08:38 PM 4 2.00 0.00 5.00 0.00 0.00 0.00
0.00 93.00 0.00
05:08:38 PM 5 0.00 0.00 0.00 0.00 0.00 0.00
0.00 100.00 0.99
05:08:38 PM 6 0.00 0.00 0.00 0.00 0.00 0.00
0.00 100.00 0.00
05:08:38 PM 7 7.00 0.00 17.00 0.00 1.00 55.00
0.00 20.00 7095.05

05:08:38 PM CPU %user %nice %sys %iowait %irq %soft
%steal %idle intr/s
05:08:39 PM all 1.12 0.00 3.62 0.00 0.12 7.86
0.00 87.28 9617.00
05:08:39 PM 0 1.00 0.00 0.00 0.00 0.00 0.00
0.00 99.00 1001.00
05:08:39 PM 1 0.00 0.00 0.00 0.00 0.00 0.00
0.00 100.00 0.00
05:08:39 PM 2 0.00 0.00 0.00 0.00 0.00 0.00
0.00 100.00 0.00
05:08:39 PM 3 2.00 0.00 7.00 0.00 0.00 1.00
0.00 90.00 0.00
05:08:39 PM 4 0.00 0.00 0.00 0.00 0.00 0.00
0.00 100.00 0.00
05:08:39 PM 5 0.00 0.00 0.00 0.00 0.00 0.00
0.00 100.00 0.00
05:08:39 PM 6 0.00 0.00 1.00 0.00 0.00 0.00
0.00 99.00 0.00
05:08:39 PM 7 6.06 0.00 21.21 0.00 1.01 62.63
0.00 9.09 8617.00

As you can see nginx only use one core not all of them even if I state
worker_processes 8;

I have used nginx-0.7.64 and used centos 5.4 compiled using just
./configure && make && make install. I have read that nginx supports
multiple cpu but as far as I see from mpstat output it doesn’t
Can anyone englighten me about that?

Regards.

2

On 01/13/2010 04:20 PM, Omer Faruk Sen wrote:

[SNIP]

As you can see nginx only use one core not all of them even if I state
worker_processes 8;

I have used nginx-0.7.64 and used centos 5.4 compiled using just
./configure&& make&& make install. I have read that nginx supports
multiple cpu but as far as I see from mpstat output it doesn’t
Can anyone englighten me about that?

I’ve seen someting similar during my tests on an 8 core system (no HT).
I
set up a default nginx with and increased the number of worker processes
to
two but when I put load on nginx only one CPU gets used while the other
stays idle.

Regards,
Dennis

3

Hello Omer,

Wednesday, January 13, 2010, 9:20:21 PM, you wrote:

Hi,

I have a 8 core (4 core and HT enabled) machine to test nginx. In my
configuration file

worker_processes 8;

events {
worker_connections 30000;
}

I have done a simple test on that 4 core here is mpstat -P ALL 1 output

05:08:35 PM CPU %user %nice %sys %iowait %irq %soft %steal %idle intr/s
05:08:36 PM all 4.12 0.00 7.62 2.12 0.25 6.99 0.00 78.90 12902.00
05:08:36 PM 0 19.00 0.00 17.00 0.00 0.00 1.00 0.00 63.00 1001.00
05:08:36 PM 1 1.00 0.00 2.00 0.00 0.00 0.00 0.00 97.00 0.00
05:08:36 PM 2 1.00 0.00 4.00 6.00 0.00 0.00 0.00 89.00 25.00
05:08:36 PM 3 1.00 0.00 1.00 0.00 0.00 0.00 0.00 98.00 0.00
05:08:36 PM 4 7.92 0.00 23.76 0.00 0.00 1.98 0.00 66.34 0.00
05:08:36 PM 5 0.00 0.00 3.03 0.00 0.00 0.00 0.00 96.97 1.00
05:08:36 PM 6 0.99 0.00 2.97 9.90 0.00 0.00 0.00 86.14 0.00
05:08:36 PM 7 2.02 0.00 7.07 0.00 2.02 52.53 0.00 36.36 11875.00

05:08:36 PM CPU %user %nice %sys %iowait %irq %soft %steal %idle intr/s
05:08:37 PM all 1.75 0.00 5.24 1.00 0.12 6.74 0.00 85.14 9524.24
05:08:37 PM 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 1011.11
05:08:37 PM 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 0.00
05:08:37 PM 2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 7.07
05:08:37 PM 3 2.97 0.00 7.92 0.00 0.00 0.00 0.00 89.11 0.00
05:08:37 PM 4 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 0.00
05:08:37 PM 5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 0.00
05:08:37 PM 6 0.00 0.00 5.00 9.00 0.00 0.00 0.00 86.00 0.00
05:08:37 PM 7 10.89 0.00 28.71 0.00 0.99 53.47 0.00 5.94 8504.04

05:08:37 PM CPU %user %nice %sys %iowait %irq %soft %steal %idle intr/s
05:08:38 PM all 2.75 0.00 5.25 0.00 0.12 7.00 0.00 84.88 8087.13
05:08:38 PM 0 8.91 0.00 10.89 0.00 0.00 0.99 0.00 79.21 991.09
05:08:38 PM 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 0.00
05:08:38 PM 2 0.00 0.00 2.00 0.00 0.00 0.00 0.00 98.00 0.00
05:08:38 PM 3 3.00 0.00 7.00 0.00 0.00 0.00 0.00 90.00 0.00
05:08:38 PM 4 2.00 0.00 5.00 0.00 0.00 0.00 0.00 93.00 0.00
05:08:38 PM 5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 0.99
05:08:38 PM 6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 0.00
05:08:38 PM 7 7.00 0.00 17.00 0.00 1.00 55.00 0.00 20.00 7095.05

05:08:38 PM CPU %user %nice %sys %iowait %irq %soft %steal %idle intr/s
05:08:39 PM all 1.12 0.00 3.62 0.00 0.12 7.86 0.00 87.28 9617.00
05:08:39 PM 0 1.00 0.00 0.00 0.00 0.00 0.00 0.00 99.00 1001.00
05:08:39 PM 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 0.00
05:08:39 PM 2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 0.00
05:08:39 PM 3 2.00 0.00 7.00 0.00 0.00 1.00 0.00 90.00 0.00
05:08:39 PM 4 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 0.00
05:08:39 PM 5 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 0.00
05:08:39 PM 6 0.00 0.00 1.00 0.00 0.00 0.00 0.00 99.00 0.00
05:08:39 PM 7 6.06 0.00 21.21 0.00 1.01 62.63 0.00 9.09 8617.00

As you can see nginx only use one core not all of them even if I state
worker_processes 8;

I have used nginx-0.7.64 and used centos 5.4 compiled using just
./configure && make && make install. I have read that nginx supports
multiple cpu but as far as I see from mpstat output it doesn’t
Can anyone englighten me about that?

It’s just because one worker is able (at least kernel decided so) to
process all requests. Try to play with ‘accept_mutex on|off’ in nginx
config.

Regards.

–
Best regards,
Denis mailto:[email protected]

4

Hi,

Have enabled accept_mutex on;

user root;
worker_processes 8;

worker_rlimit_nofile 32000;

#pid logs/nginx.pid;

events {
accept_mutex on;
worker_connections 30000;
}

but still only one cpu is busy while others stay in idle mode? Any
sugggestions?

Regards.