xref: /freebsd/usr.sbin/rpc.statd/rpc.statd.8 (revision 41466b50c1d5bfd1cf6adaae547a579a75d7c04e)
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3.\" Copyright (c) 1995 A.R.Gordon, andrew.gordon@net-tel.co.uk
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34.\" $FreeBSD$
35.\"
36.Dd September 19, 1995
37.Dt RPC.STATD 8
38.Os
39.Sh NAME
40.Nm rpc.statd
41.Nd host status monitoring daemon
42.Sh SYNOPSIS
43.Nm
44.Op Fl d
45.Sh DESCRIPTION
46.Nm Rpc.statd
47is a daemon which co-operates with rpc.statd daemons on other hosts to provide
48a status monitoring service.  The daemon accepts requests from
49programs running on the local host (typically,
50.Xr rpc.lockd 8 ,
51the NFS file locking daemon) to monitor the status of specified
52hosts.  If a monitored host crashes and restarts, the remote daemon will
53notify the local daemon, which in turn will notify the local program(s)
54which requested the monitoring service.  Conversely, if this host crashes
55and re-starts, when the
56.Nm
57re-starts, it will notify all of the hosts which were being monitored
58at the time of the crash.
59.Pp
60The following option is available:
61.Bl -tag -width indent
62.It Fl d
63Cause debugging information to be written to syslog, recording
64all RPC transactions to the daemon.  These messages are logged with level
65LOG_DEBUG and facility LOG_DAEMON.  Error conditions are logged irrespective
66of this option, using level LOG_ERR.
67.El
68.Pp
69The
70.Nm
71daemon must NOT be invoked by
72.Xr inetd 8
73because the protocol assumes that the daemon will run from system start time.
74Instead, it should be run from
75.Xr rc 8
76after the network has been started.
77.Sh FILES
78.Bl -tag -width /usr/include/rpcsvc/sm_inter.x -compact
79.It Pa /var/db/statd.status
80non-volatile record of currently monitored hosts.
81.It Pa /usr/include/rpcsvc/sm_inter.x
82RPC protocol specification used by local applications to register monitoring requests.
83.El
84.Sh SEE ALSO
85.Xr syslog 3 ,
86.Xr rc 8 ,
87.Xr rpc.lockd 8
88.Sh BUGS
89There is no means for the daemon to tell when a monitored host has
90disappeared permanently (eg. catastrophic hardware failure), as opposed
91to transient failure of the host or an intermediate router.  At present,
92it will re-try notification attempts at frequent intervals for 10 minutes,
93then hourly, and finally gives up after 24 hours.
94.Pp
95The protocol requires that symmetric monitor requests are made to both
96the local and remote daemon in order to establish a monitored relationship.
97This is convenient for the NFS locking protocol, but probably reduces the
98usefulness of the monitoring system for other applications.
99.Pp
100The current implementation uses more than 1Kbyte per monitored host in
101the status file (and also in VM).  This may be inefficient for NFS servers
102with large numbers of clients.
103.Sh STANDARDS
104The implementation is based on the specification in X/Open CAE Specification
105C218, "Protocols for X/Open PC Interworking: XNFS, Issue 4", ISBN 1 872630 66 9
106