nefu(1) User Commands nefu(1)NAMEnefu - network monitoring daemon
SYNOPSISnefu [ -d passes ] [ -D domain ] [ -f file ] [ -h ] [ -H ] [ -l facil‐
ity ] [ -m mask ] [ -M domain ] [ -n ] [ -N ] [ -p seconds ] [ -r sec‐
onds ] [ -R ] [ -S ] [ -s seconds ] [ -u uname ] [ -V ] [ -W seconds ]
DESCRIPTIONnefu is a daemon used for monitoring services available over a network.
nefu must be started as root. Once started, nefu changes its UID and
directory to those of the user nefu, unless a different user is speci‐
fied with the -u option. nefu may use external programs to monitor
services. External tests should reside under $HOME/shelltests.
nefu's input is a dependency map of services to monitor or a file spec‐
ified with the -f option. See nefu.conf(5) for the dependency map syn‐
tax.
nefu's dependency map consists of two types of machines: leaf and
internal. Internal machines are network dependencies for other
machines; leaf machines have local services only. When a service on a
machine is tested it will be found to be in one of three states: UP,
DOWN, or MAYBE_DOWN. A service in the DOWN state has responded in a
manner that conclusively proves it is unavailable (e.g., a "Connection
Refused" response). A service that fails in an inconclusive manner
(e.g., a timeout) is considered to be MAYBE_DOWN. If a service transi‐
tions from UP or DOWN to MAYBE_DOWN, and all of the network dependen‐
cies between the monitor machine and the target are verified to be UP,
the service is tested a second time. If the service fails inconclu‐
sively a second time it is MAYBE_DOWN. A BOUNCE is logged for a ser‐
vice that fails inconclusively once, but then replies conclusively
after its dependency path is verified.
If a machine's domain name is not found in DNS, or if it's domain name
resolves to multiple IP addresses, it is ignored by the monitor and
reported as down. All machines in this state are re-queried every so
many passes, as set by the -d passes flag. By default, re-queries
every 10 passes. If passes is set to 0, DNS is never re-queried.
nefu's pass time is how long it takes to complete a single pass through
its dependency tree testing all reachable leaf machines. If a pass
takes less time than the minimum time, nefu will sleep for the remain‐
der of the pass. In the event that a pass should take longer than the
minimum pass time nefu will begin its next pass immediately. Default
pass time is 60 seconds, or it can be set with the -p option. Service
delay time is the time between each test during a pass. Default ser‐
vice delay time is 0 seconds. It can be set with the -s option.
nefu's last complete pass time information is published in its .project
file. A global maximum timeout value for al tests can be set with the
-W flag.
syslog(3) is used to log informational messages. syslog facility can
be set with the -l option, default is DAEMON. nefu logs different
events at different syslog levels: LOG_DEBUG is for startup and pass
time information, LOG_INFO is used by individual tests to log trip time
information and for sendmail confirmations, LOG_NOTICE is where the
monitor logs BOUNCE and state change information, and LOG_ERR is
reserved for local system errors. See syslog.conf(4) for more informa‐
tion.
When nefu detects a state change in a service it is reported via send‐
mail, published in .plan and index.html, and logged with syslog. If
the -S suppress first pass paging has been elected, nefu will not use
sendmail to generate reports during the first pass.
Unless HTML output is disabled nefu publishes its status page, depen‐
dency map, machine list, and responsibility code information as HTML
pages. By default, nefu's status page has a refresh tag for as many
seconds as nefu's pass time. The -r HTML refresh tag can be used to
set a different refresh interval, in seconds, with 0 disabling refresh‐
ment. HTML pages generated by nefu can optionally have a user-created
header and footer. Any user created header.html must contain the
</HEAD> and <BODY> HTML tags. nefu will keep a list of snapshots of
passes where state changes occured if enabled with the -H HTML history
option.
For compatability with some email-to-page gateways, nefu can be run in
redundant mode with the -R option. nefu will repeat the information
normally contained only in an email's subject in to the body of the
message as well. nefu's email domain defaults to the name of the
localhost, unles set by the -D option.
OPTIONS-d passes re-query DNS for failed domain names every so many
passes. Default is 10.
-D domain specify the domain for nefu's email. Default is the
local hostname.
-f file specify a config file instead of stdin.
-h do not output HTML.
-H log history to HTML.
-l facility syslog facility. Options are USER, DAEMON, LOCAL0,
LOCAL1, LOCAL2, LOCAL3, LOCAL4, LOCAL5, LOCAL6,
LOCAL7. Default is DAEMON.
-m mask umask for output files. Default is 022.
-M domain Master domain for the DNS test. Default is "."
-N quit after outputting HTML.
-n print the dependency tree to stdout and exit.
-p seconds minimum pass time in seconds. Default is 60.
-r seconds HTML refresh interval in seconds. Default is pass
time. 0 disables.
-R Generate emails with redundant information.
-S Supress paging during the monitor's first pass.
-s seconds service delay time in seconds. Default is 0.
-u uname run as uname. Default is "nefu".
-V displays the version of nefu and exits.
-W seconds Global test maximum wait time, in seconds.
FILES
nefu.conf nefu's dependency map
$HOME/.plan current network status
$HOME/.project last pass time information
$HOME/public_html/ HTML output directory
$HOME/public_html/header.html
optional header applied to all generated HTML pages
$HOME/public_html/footer.html
optional footer applied to all generated HTML pages
$HOME/shelltests/ external script directory for nefu shell tests
SEE ALSOnefu.conf(4), syslog.conf(4), finger(1), sendmail(1)RSUG October 2002 nefu(1)
