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
Speaks the HTTP protocol to fetch a URL from an HTTP server.
The http_t monitor can measure page delivery latency and report
failures if a minimum transfer speed is not met. There are several
variants of the HTTP monitor for use in different situations.
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 Asynchronous SNMP
Calculate the uptime and downtime of any SNMP-capable host.
Hundreds of hosts can be polled in a few seconds using the
asynchronous method.
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.
mSQL and MySQL databases
The msql-mysql monitor connects to the database in question
and list the tables to ensure that the host is responding to
queries.
Network latency
up_rtt.monitor uses the UDP or TCP echo service to measure
the round-trip time between the monitoring server and a
set of hosts. If the measured latency exceeds a minimum,
then a failure is reported.
Sun RPC Services
The RPC monitor can call the RPC NULL function to determine
if a server is responding to queries. This method can be used
to poll NIS, NFS, mountd, and other popular services which use
Sun RPC.
Foundry chassis
Report power supply, fan, temperature, module failures
in Foundry BigIron and FastIron routers and bridges.
Compaq Presario chassis
Report power supply, fan, and temperature problems with
Presario systems via the "Insight Manager" SNMP agent.
Brocade SilkWorm FCAL switches
Report PSU, fan, and temperature, PHY, and link problems.
