Squid SNMP

Pack assets

Monitored objects

• Cache Usage
• Protocol statistics

Collected metrics & status

Caches-Usage

Metric name	Description	Unit
cache.cpu.utilization.percentage	Cpu usage	%
cache.memory.usage.bytes	Memory usage	B
cache.filedescriptors.count	Number of file descriptors	count
cache.objects.count	Number of object stored	count

Protocol-Stats

• HTTP statistics

Metric name	Description	Unit
http.hits.percentage	HTTP hits rate	%
http.errors.count	Number of HTTP errors	count
http.traffic.in.bitspersecond	HTTP traffic in	b/s
http.traffic.out.bitspersecond	HTTP traffic out	b/s

• ICP statistics

Metric name	Description	Unit
icp.traffic.in.bitspersecond	ICP traffic in	b/s
icp.traffic.out.bitspersecond	ICP traffic out	b/s

• Cache statistics

Metric name	Description	Unit
cache.server.traffic.in.bitspersecond	Cache server traffic in	b/s
cache.server.traffic.out.bitspersecond	Cache server traffic out	b/s
cache.clients.count	Current number of clients: %s	count

Prerequisites

To use this pack, the SNMP service must be properly configured on your Squid proxy. Squid provides an official documentation to achieve this: https://wiki.squid-cache.org/Features/Snmp

Network flow

The Squid proxy must be reachable from the Centreon Poller on the UDP/161 SNMP port.

Setup

Online License

1. Install the Centreon package on every Centreon poller expected to monitor your Squid proxy ressources:

yum install centreon-plugin-Applications-Squid-Snmp

2. On the Centreon Web interface, install the Squid SNMP Centreon Monitoring Connector on the Configuration > Monitoring Connector Manager page

Offline License

1. Install the Centreon package on every Centreon poller expected to monitor your Squid proxy ressources:

yum install centreon-plugin-Applications-Squid-Snmp

2. Install the Squid SNMP Centreon Monitoring Connector RPM on the Centreon Central server:

yum install centreon-pack-applications-squid-snmp

3. On the Centreon Web interface, install the Squid SNMP Centreon Monitoring Connector on the Configuration > Monitoring Connector Manager page

Configuration

Host

• Log into Centreon and add a new Host through Configuration > Hosts.
• Fill the "Name", "Alias" & "IP Address / DNS" fields according to your Squid proxy settings
• Select the Applications-Squid-Snmp-custom template to apply to the Host

When using SNMP v3, use the SNMPEXTRAOPTIONS Macro to add specific authentication parameters More information in the Troubleshooting SNMP section.

Mandatory	Name	Description
	SNMPEXTRAOPTIONS	Configure your own SNMPv3 credentials combo

How to check in the CLI that the configuration is OK and what are the main options for ?

Once the plugin installed, log into your Centreon Poller CLI using the centreon-engine user account and test the Plugin by running the following command:

/usr/lib/centreon/plugins//centreon_squid_snmp.pl \
    --plugin=apps::squid::snmp::plugin \
    --mode=cache-usage \
    --hostname='10.0.0.1' \
    --snmp-version='2c' \
    --snmp-community='my-snmp-community' \
    --filter-counters='' \
    --warning-cpu='80' \
    --critical-cpu='90' \
    --use-new-perfdata

Expected command output is shown below:

OK : Cpu usage: 30 % Memory usage: 265289728 B Number of file descriptors: 45 Number of object stored: 23 | 'cache.cpu.utilization.percentage'=30%;;;0;100 
'cache.memory.usage.bytes'=265289728B;;;0; 'cache.filedescriptors.count'=45;;;0; 'cache.objects.count'=23;;;0; 

This command would trigger a WARNING alarm if the cpu utilization is reported as over 80% (--warning-cpu='80') and a CRITICAL alarm if over 90% (--critical-cpu='90').

All available options for a given mode can be displayed by adding the --help parameter to the command:

/usr/lib/centreon/plugins//centreon_squid_snmp.pl  \
    --plugin=apps::squid::snmp::plugin  \
    --mode=cache-usage  \
    --help

All available options for a given mode can be displayed by adding the --list-mode parameter to the command:

 /usr/lib/centreon/plugins//centreon_squid_snmp.pl  \
    --plugin=apps::squid::snmp::plugin  \
    --list-mode

Troubleshooting

UNKNOWN: SNMP GET Request : Timeout

If you get this message, you're probably facing one of theses issues:

• Your SNMP server isn't started or misconfigured
• An external device is blocking your request (firewall, ...)

UNKNOWN: SNMP GET Request : Cant get a single value

This message generally means that SNMP privileges are not wide enough for the mode/Plugin to work properly.