Cobra Forum

Question: High CPU usage by Nginx is shown in Health Monitor


Applicable to:

Plesk Onyx for Linux


Symptoms

• The high CPU usage by Nginx can be found in Plesk > Health Monitoring.

• Many Nginx processes as below can be found on the server:

# top -c
19296 nginx 20 0 318720 223848 2212 S 0.3 2.1 0:00.23 nginx: worker process

# top -c
19289 nginx 20 0 318720 223848 2212 S 0.3 2.1 0:00.23 nginx: worker process is shutting down


Cause

Incorrect value of worker_connections directive.


Resolution

1.Log into the server via SSH.

2.Create a backup for Nginx configuration file:

# cp /etc/nginx/nginx.conf{,.orig}

3.Get the number of CPU cores (in the example below this value is equal to 4):
# cat /proc/cpuinfo | grep processor | wc -l
4

4.Using the vi text editor open the/etc/nginx/nginx.conf file and change the value for the worker_connections equals to 1024 * number of CPU cores:
worker_connections 4096;
5.Restart the Nginx service to apply changes:

# service nginx restart