Question

Why doesn’t Nagios have a check_memory as part of the initial set of plugins that come by default? Like check_http, check_load etc?

Thanks!

Answer 1

According to Nagios Plugins the plugins in that project need to meet certain criteria, here is a statement from the FAQ:

There are two types of plugins included in the distribution:

• Plugins that are officially maintained by the nagios plugin
  developer team
• Plugins that are distributed in the contrib directory

Sooner or later all the contrib plugins should be hosted at the
official 3rd Party Nagios plugin page Nagios Exchange

Contrib plugins have to be installed manually. They are not affected
by the build process.

Here is a list of the actively maintained Plugins:

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_flexlm, check_fping, check_ftp,
check_game, check_hpjd, check_http, check_icmp, check_ide_smart,
check_ifoperstatus, check_ifstatus, check_imap, check_ircd,
check_jabber, check_ldap, check_load, check_log, check_mailq,
check_mrtg, check_mrtgtraf, check_mssql, check_mysql,
check_mysql_query, check_nagios, check_netdns, check_nntp,
check_nntps, check_nt, check_ntp_peer, check_ntp_time, check_nwstat,
check_oracle, check_overcr, check_pgsql, check_ping, check_pop,
check_procs, check_radius, 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

And these plugins are currently distributed in the contrib directory:

check_adptraid, check_apache, check_apc_ups, check_appletalk,
check_arping, check_asterisk, check_axis, check_backup,
check_bgpstate, check_breeze, check_cluster, check_cluster2,
check_compaq_insight, check_cpqarray, check_digitemp,
check_dlswcircuit, check_dns_random, check_email_loop,
check_fan_cpq_present, check_fan_fsc_present, check_flexlm,
check_frontpage, check_hltherm, check_hprsc,
check_http-with-client-certificate, check_hw,
check_ica_master_browser, check_ica_metaframe_pub_apps,
check_ica_program_neigbourhood, check_inodes, check_inodes-freebsd,
check_ipxping, check_javaproc, check_joy, check_linux_raid,
check_lmmon, check_log2, check_lotus, check_maxchannels,
check_maxwanstate, check_mem, check_ms_spooler, check_mssql,
check_nagios, check_nagios_db, check_nagios_db_pg, check_netapp,
check_nmap, check_oracle_instance, check_oracle_tbs,
check_ora_table_space, check_pcpmetric, check_pfstate, check_qmailq,
check_rbl, check_remote_nagios_status, check_rrd_data, check_sap,
check_smart, check_smb, check_snmp_disk_monitor, check_snmp_printer,
check_snmp_process_monitor, check_snmp_procs, check_sockets,
check_temp_cpq, check_temp_fsc, check_timeout, check_traceroute,
check_traceroute-pure_perl, check_uptime, check_vcs, check_wave,
check_wins

As you can see there isn’t an official check_memory plugin included in the maintained plugins, however you can find plugins that do support what you are looking for on Naigos Exchange.