onnode
1
onnode
run commands on ctdb nodes
onnode [OPTION] ... NODES COMMAND ...
DESCRIPTION
onnode is a utility to run commands on a specific node of a CTDB
cluster, or on all nodes.
The NODES option specifies which node to run a command on. You
can specify a numeric node number (from 0 to N-1) or a
descriptive node specification (see DESCRIPTIVE NODE
SPECIFICATIONS below). You can also specify lists of nodes,
separated by commas, and ranges of numeric node numbers,
separated by dashes. If nodes are specified multiple times then
the command will be executed multiple times on those nodes. The
order of nodes is significant.
The COMMAND can be any shell command. The onnode utility uses
ssh or rsh to connect to the remote nodes and run the command.
DESCRIPTIVE NODE SPECIFICATIONS
The following descriptive node specification can be used in
place of numeric node numbers:
all
All nodes.
ok | healthy
All nodes that are not disconnected, banned, disabled or
unhealthy.
con | connected
All nodes that are not disconnected.
rm | recmaster
The current recovery master.
OPTIONS
-c
Execute COMMAND in the current working directory on the
specified nodes.
-p
Run COMMAND in parallel on the specified nodes. The
default is to run COMMAND sequentially on each node.
-q
Do not print node addresses. Normally, onnode prints
informational node addresses if more than one node is
specified. This overrides -v.
-v
Print a node addresses even if only one node is specified.
Normally, onnode prints informational node addresses when
more than one node is specified.
-h, --help
Show a short usage guide.
EXAMPLES
The following command would show the process ID of ctdb on all nodes
onnode all pidof ctdbd
The following command would show the last 5 lines of log on each
node, preceded by the node's hostname
onnode all "hostname; tail -5 /var/log/log.ctdb"
The following command would restart the ctdb service on all nodes.
onnode all service ctdb restart
The following command would run ./foo in the current working
directory, in parallel, on nodes 0, 2, 3 and 4.
onnode -c -p 0,2-4 ./foo
FILES
/etc/ctdb/nodes
Contains a list of each node's IP address or hostname.
/etc/ctdb/onnode.conf
If this file exists it is sourced by onnode. The main
purpose is to allow the administrator to set $SSH to
something other than "ssh". In this case the -t option is
ignored. For example, the administrator may choose to use
use rsh instead of ssh.
SEE ALSO
ctdbd(1), ctdb(1),
COPYRIGHT/LICENSE
Copyright (C) Andrew Tridgell 2007
Copyright (C) Ronnie sahlberg 2007
Copyright (C) Martin Schwenke 2008
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or (at
your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, see http://www.gnu.org/licenses/.