Service Monitors Included in Version 0.37l

ICMP echo (ping)

Efficient host reachability via ICMP echo, using fping, which multiplexes pings using a single process. If a group of hosts is pinged, and if more than one fails, then the collective timeout before the monitor script returns is what it would normally be if you're pinging only one host.

SMTP

SMTP connectivity is tested by connecting to the SMTP port on one or more servers, listening for a "220" response, sending a "QUIT", and waiting for a "221" response and then a shutdown.

Telnet

Waits for an actual login prompt to determine if the service is working. This uses Wietse Venema's tcp_scan utility.

FTP

FTP connectivity is tested by connecting to the FTP server, sending a "quit", and waiting for the appropriate response.

NNTP

Similar to SMTP testing, speaks the NNTP protocol.

HTTP

Similar to SMTP, speaks the HTTP protocol to fetch a page.

POP-3

Similar to SMTP, speaks POP-3 to connect and then log out.

IMAP

Similar to POP-3, speaks IMAP to connect and then log out.

TCP-based services

Any simple TCP-based service can be tested. mon comes with a "tcp.monitor" utility (which is a wrapper for Wietse Venema's tcp_monitor from the Satan distribution). This will send output to a server, and for a particular response, with a timeout.

Disk space

Disk space monitoring via NFS or local mounts.

Uptime via SNMP

Calculate the uptime and downtime of any SNMP-capable host.

HP Printers via SNMP

Using SNMP, hpnp.monitor polls HP printers with JetDirect interfaces and can detect paper outages, paper jams, toner cartridge problems, and more. When a failure is detected, it can report the message which is displayed on the printer's LCD, e.g. "TRAY 2 EMPTY".

Processes via SNMP

process.monitor polls the UCD SNMP agents on some number of hosts and reports problems with particular processes. This monitor is useful to detect if a particular process has died off.

Network Appliance free space via SNMP

netappfree.monitor polls Network Appliance filers for free space on each exported filesystem. It does not require that you mount the filesystems on the mon host. Per-filesystem low watermarks are configured in a separate configuration file for easy changing without resetting the mon server.

Network Appliance quota trees via SNMP

na_quote.monitor can monitor free space on multiple quota trees. Currently a work-in-progress.

LDAP

ldap.monitor searches an LDAP server for objects which match a particular filter.

DNS

dns.monitor queries a zone master for base information, and then queries one or more secondaries, comparing the serial number found in the SOA record to that of the master.

Dial-in terminal servers

dialin.monitor can periodically dial in to a terminal server or some other modem host and report whether or not a connection was successfully made to the remote host, and if a login prompt was obtained.