NAME
dcnodesd — maintain cluster client status information
SYNOPSIS
dcnodesd
[-r
retransmit_interval]
DESCRIPTION
dcnodesd
provides information on the state of cluster clients.
dcnodesd
executes on all nodes of a cluster. On clients, it periodically
sends ``keepalive'' packets to the
dcnodesd
running on the cluster server.
dcnodesd
gathers this information from clients and provides it to
the
dcnodes_status()
function
(see
dcnodes_status(3X)).
dcnodesd
is started on cluster servers and clients by entries in
/etc/inittab.
When started on a cluster server,
dcnodesd
collects packets from cluster clients and resets timestamps.
When started on a cluster client,
dcnodesd
periodically send keepalive packets
to the cluster server.
Options
dcnodesd
recognizes the following options:
- -r retransmit_interval
The
dcnodesd
running on a cluster clients periodically sends messages to the server.
When the server receives one of these messages, it updates a timestamp for
the client from which the message was received. When the
dcnodesd
on the server provides information to
dcnodes_status(),
it provides both the client timestamps and a current timestamp. The
difference between these two values is used to determine if a client
is active or not. By using the
-r
option, the retransmission interval can be specified for the
dcnodesd
running on a client. It defaults to once every 5 seconds.
Client timestamps have a lifespan which defaults to 10 seconds. A client
with a timestamp older than 10 seconds is considered inactive.
The retransmission interval should not require adjustment, but on
a heavily loaded client and/or network, it can be shortened to increase
the likelihood of updating the client timestamp regularly.
DIAGNOSTICS
dcnodesd
writes warnings or error messages to standard error as appropriate.
dcnodesd
uses syslog() for error and warning messages once it has initiated
its network connections.
AUTHOR
dcnodesd
was developed by
HP.
FILES
- /etc/clients.dc
list of configured cluster client nodes that receive root service from a system
- /etc/bootptab
control file for
bootpd
(see
bootpd(1M))
that contains most of the client information returned by
dcnodes
Printable version
