rwhod(1m) [hpux man page]
rwhod(1M) rwhod(1M) NAME
rwhod - system status server SYNOPSIS
DESCRIPTION
is the server that maintains the database used by and (see rwho(1) and ruptime(1)). sends status information to and receives status infor- mation from other nodes on the local network that are running is started at system boot time if the RWHOD variable is set to 1 in the file As an information sender, it periodically queries the state of the system and constructs status messages that are broadcast on a network. As an information receiver, it listens for other servers' status messages, validates them, then records them in a collection of files located in the directory. By default, both sends and receives information. also supports the following options: Configures server to be an information sender only. Configures server to be an information receiver only. Status messages are generated approximately once every three minutes. transmits and receives messages at the port indicated in the service specification (see services(4)). The messages sent and received, are of the form: All fields are converted to network byte order before transmission. System load averages are calculated from the number of jobs in the run queue over the last 1-, 5- and 15-minute intervals. The host name included is the one returned by the system call (see gethostname(2)). The array at the end of the message contains information about the users logged in on the sending machine. This information includes the contents of the entry for each non-idle terminal line and a value indicating the time since a character was last received on the terminal line (see utmp(4)). discards received messages if they did originate at a server's port, or if the host's name, as specified in the message, contains any unprintable ASCII characters. Valid messages received by are placed in files named in the directory. These files contain only the most recent message in the format described above. WARNINGS
does not relay status information between networks. Users often incorrectly interpret the server dying as a machine going down. AUTHOR
was developed by the University of California, Berkeley. FILES
Information about other machines. SEE ALSO
rwho(1), ruptime(1), gethostname(2), services(4), utmp(4). rwhod(1M)
Check Out this Related Man Page
in.rwhod(1M) System Administration Commands in.rwhod(1M) NAME
in.rwhod, rwhod - system status server SYNOPSIS
/usr/sbin/in.rwhod [ -m [ttl]] DESCRIPTION
in.rwhod is the server which maintains the database used by the rwho(1) and ruptime(1) programs. Its operation is predicated on the abil- ity to broadcast or multicast messages on a network. in.rwhod operates as both a producer and consumer of status information. As a producer of information it periodically queries the state of the system and constructs status messages which are broadcast or multicast on a network. As a consumer of information, it listens for other in.rwhod servers' status messages, validating them, then recording them in a collection of files located in the directory /var/spool/rwho. The rwho server transmits and receives messages at the port indicated in the rwho service specification, see services(4). The messages sent and received are defined in /usr/include/protocols/rwhod.h and are of the form: struct outmp { char out_line[8]; /* tty name */ char out_name[8]; /* user id */ long out_time; /* time on */ }; struct whod { char wd_vers; char wd_type; char wd_fill[2]; int wd_sendtime; int wd_recvtime; char wd_hostname[32]; int wd_loadav[3]; int wd_boottime; struct whoent { struct outmp we_utmp; int we_idle; } wd_we[1024 / sizeof (struct whoent)]; }; All fields are converted to network byte order prior to transmission. The load averages are as calculated by the w(1) program, and repre- sent load averages over the 1, 5, and 15 minute intervals prior to a server's transmission. The host name included is that returned by the uname(2) system call. The array at the end of the message contains information about the users who are logged in to the sending machine. This information includes the contents of the utmpx(4) entry for each non-idle terminal line and a value indicating the time since a char- acter was last received on the terminal line. Messages received by the rwho server are discarded unless they originated at a rwho server's port. In addition, if the host's name, as specified in the message, contains any unprintable ASCII characters, the message is discarded. Valid messages received by in.rwhod are placed in files named whod.hostname in the directory /var/spool/rwho. These files contain only the most recent message, in the format described above. Status messages are generated approximately once every 3 minutes. OPTIONS
The following options are supported: -m [ ttl ] Use the rwho IP multicast address (224.0.1.3) when transmitting. Receive announcements both on this multicast address and on the IP broadcast address. If ttl is not specified in.rwhod multicasts on all interfaces but with the IP TimeToLive set to 1 (that is, packets are not forwarded by multicast routers.) If ttl is specified in.rwhod only transmits packets on one interface and setting the IP TimeToLive to the specified ttl. FILES
/var/spool/rwho/whod.* information about other machines ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWrcmds | +-----------------------------+-----------------------------+ SEE ALSO
ruptime(1), rwho(1), w(1), uname(2), services(4), utmpx(4), attributes(5) WARNINGS
This service can cause network performance problems when used by several hosts on the network. It is not run at most sites by default. If used, include the -m multicast option. NOTES
This service takes up progressively more network bandwidth as the number of hosts on the local net increases. For large networks, the cost becomes prohibitive. in.rwhod should relay status information between networks. People often interpret the server dying as a machine going down. SunOS 5.10 8 Dec 2001 in.rwhod(1M)