CPU Usage Checks

The examples in this KB article focus on CPU usage. If you are interested in Load checks please refer to the Load Checks KB article.

The CPU Used - Percentage section of this KB article is the only one that contains check commands.

These sections provide information as to why these check methods are not possible and offer links to alternative methods.

CPU Free - Percentage
CPU Free - Specific Value
CPU Used - Specific Value

CPU Free - Percentage

Nagios Plugins

Nagios Plugins does not include a CPU Usage check, please refer to the Load Checks KB article.

NCPA

NPCA includes a CPU module however it only reports percentage used, please see the CPU Used - Percentage section.

NSClient++ via check_nt

NSClient++ does not include a CPU Usage check, please refer to the Load Checks KB article.

NSClient++ via check_nrpe

NSClient++ does not include a CPU Usage check, please refer to the Load Checks KB article.

WMI

Check WMI Plus includes a CPU module however it only reports percentage used, please see the CPU Used - Percentage section.

SNMP

The check_snmp_load_wizard.pl plugin only reports percentage used, please see the CPU Used - Percentage section.

CPU Free - Specific Value

Nagios Plugins

Nagios Plugins does not include a CPU Usage check, please refer to the Load Checks KB article.

NCPA

NPCA includes a CPU module however it only reports percentage used, please see the CPU Used - Percentage section.

NSClient++ via check_nt

NSClient++ does not include a CPU Usage check, please refer to the Load Checks KB article.

NSClient++ via check_nrpe

NSClient++ does not include a CPU Usage check, please refer to the Load Checks KB article.

WMI

Check WMI Plus includes a CPU module however it only reports percentage used, please see the CPU Used - Percentage section.

SNMP

The check_snmp_load_wizard.pl plugin only reports percentage used, please see the CPU Used - Percentage section.

CPU Used - Percentage

These are CPU Usage checks based on percentages, they are best used when you want to be notified if the amount of used CPU exceeds a threshold.

Nagios Plugins

Nagios Plugins does not include a CPU Usage check, please refer to the Load Checks KB article.

NCPA

NPCA includes a CPU usage module. The thresholds are triggered if the used CPU is greater than the supplied value.

Unit:	%
Warning:	90% Used
Critical:	95% Used

Command:

./check_ncpa.py -H 10.25.254.50 -t Str0ngT0k3n -M cpu/percent --warning 90 --critical 95

Output:

OK: Percent was 3.00 %, 1.00 %, 5.00 %, 2.00 %, 1.00 %, 1.00 %, 21.20 %, 2.00 % | 'percent_0'=3.00%;90;95; 'percent_1'=1.00%;90;95; 'percent_2'=5.00%;90;95; 'percent_3'=2.00%;90;95; 'percent_4'=1.00%;90;95; 'percent_5'=1.00%;90;95; 'percent_6'=21.20%;90;95; 'percent_7'=2.00%;90;95;

From the previous output you can see that this system has 8 CPU Cores. The aggregate=avg argument allows you to check the average percent over all cores.

Command:

./check_ncpa.py -H 10.25.254.50 -t Str0ngT0k3n -M cpu/percent -q aggregate=avg --warning 90 --critical 95

Output:

OK: Percent was 3.49 % | 'percent'=3.49%;90;95;

NSClient++ via check_nt

NSClient++ does not include a CPU Usage check, please refer to the Load Checks KB article.

NSClient++ via check_nrpe

NSClient++ does not include a CPU Usage check, please refer to the Load Checks KB article.

WMI

Check WMI Plus includes a CPU usage module. The thresholds are triggered if the used CPU is greater than the supplied value.

Unit:	%
Warning:	90% Used
Critical:	95% Used

Command:

./check_wmi_plus.pl -H 10.25.14.3 -u wmiagent -p Str0ngP@ssw0rd -m checkcpu -w 90 -c 95

Output:

OK (Sample Period 300 sec) - Average CPU Utilisation 0.31%|'Avg CPU Utilisation'=0.31%;90;95;

SNMP

The check_snmp_load_wizard.pl plugin allows you to check CPU usage. The thresholds are triggered if the used CPU is greater than the supplied value.

Unit:	%
Warning:	90% Used
Critical:	95% Free

Command:

./check_snmp_load_wizard.pl -H 10.25.13.15 -C public --v2c -w 80 -c 90 -f

Output:

1 CPU, load 1.0% < 80% : OK | cpu_prct_used=1%;80;90

CPU Used - Specific Value

Nagios Plugins

Nagios Plugins does not include a CPU Usage check, please refer to the Load Checks KB article.

NCPA

NPCA includes a CPU module however it only reports percentage used, please see the CPU Used - Percentage section.

NSClient++ via check_nt

NSClient++ does not include a CPU Usage check, please refer to the Load Checks KB article.

NSClient++ via check_nrpe

NSClient++ does not include a CPU Usage check, please refer to the Load Checks KB article.

WMI

Check WMI Plus includes a CPU module however it only reports percentage used, please see the CPU Used - Percentage section.

SNMP

The check_snmp_load_wizard.pl plugin only reports percentage used, please see the CPU Used - Percentage section.

Final Thoughts

For any support related questions please visit the Nagios Support Forums at:

http://support.nagios.com/forum/