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nefu(1) User Commands nefu(1)
NAME
nefu - network monitoring daemon
SYNOPSIS
nefu [ -d passes ] [ -D domain ] [ -f file ] [ -h ] [ -H ] [
-l facility ] [ -m mask ] [ -M domain ] [ -n ] [ -N ] [ -p seconds ] [
-r seconds ] [ -R ] [ -S ] [ -s seconds ] [ -u uname ] [ -V ] [
-W seconds ]
DESCRIPTION
nefu 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
specified 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
specified with the -f option. See nefu.conf(5) for the dependency map
syntax.
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
transitions from UP or DOWN to MAYBE_DOWN, and all of the network
dependencies between the monitor machine and the target are verified to
be UP, the service is tested a second time. If the service fails
inconclusively a second time it is MAYBE_DOWN. A BOUNCE is logged for
a service 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
remainder 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 service 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
information.
When nefu detects a state change in a service it is reported via
sendmail, 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,
dependency 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
refreshment. 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 ALSO
nefu.conf(4), syslog.conf(4), finger(1), sendmail(1)
RSUG October 2002 nefu(1)