Monitoring - Nagios
About
Nagios is a monitoring platform.
Architecture
NRPE
NRPE is an addon that allows you to execute plugins remotely on Linux/Unix hosts.
Passive Checks
- An external application checks the status of a host or service.
- The external application writes the results of the check to the external command file.
- The next time Nagios Core reads the external command file it will place the results of all checks into a queue for later processing.
Check utility
Nagios check utilit may be used by collector. Example : Telegrah
Plugin always print something to STDOUT that tells if the service is working or why it is failing.
Example
/usr/local/nagios/libexec/check_load -w 5,6,7 -c 7,8,9
OK - load average: 0.49, 0.24, 0.15|load1=0.490;5.000;7.000;0; load5=0.240;6.000;8.000;0; load15=0.150;7.000;9.000;0;
The output structure is described in the plugin API section
- OK is the return code based on the POSIX spec of returning a positive value
- followed by Performance Data
'label'=value[UOM];[warn];[crit];[min];[max]
Help
check_load -help
List
- check_apt
- check_breeze
- check_by_ssh
- check_clamd
- check_cluster
- check_dhcp
- check_dig
- check_disk
- check_disk_smb
- check_dns
- check_dummy
- check_file_age
- check_file_test.sh
- check_flexlm
- check_ftp
- check_hpjd
- check_http
- check_icmp
- check_ide_smart
- check_ifoperstatus
- check_ifstatus
- check_imap
- check_ircd
- check_jabber
- check_load. See CPU - (System) Load Average
- check_log
- check_mailq
- check_mem.sh
- check_mrtg
- check_mrtgtraf
- check_multiple_files_test.sh
- check_nagios
- check_nntp
- check_nntps
- check_nrpe
- check_nt
- check_ntp
- check_ntp_peer
- check_ntp_time
- check_nwstat
- check_opmnctl_status.sh
- check_oracle
- check_oracle_coredumps.sh
- check_overcr
- check_ping
- check_pop
- check_procs
- check_pvh_tar_backup.sh
- check_real
- check_rpc
- check_sensors
- check_simap
- check_smtp
- check_snmp
- check_spop
- check_ssh
- check_ssmtp
- check_swap
- check_tcp
- check_time
- check_udp
- check_ups
- check_users
- check_wave