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Manual Reference Pages  -  NEFU (1)


nefu - network monitoring daemon


See Also


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 ]


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.


-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.


nefu.conf nefu’s dependency map
$HOME/.plan current network status
$HOME/.project last pass time information
$HOME/public_html/ HTML output directory
  optional header applied to all generated HTML pages
  optional footer applied to all generated HTML pages
$HOME/shelltests/ external script directory for nefu shell tests


nefu.conf(4), syslog.conf(4), finger(1), sendmail(1)
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RSUG NEFU (1) October 2002

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