ONNODE(1)

NAME
onnode - run commands on ctdb nodes

SYNOPSIS

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.

any
    A node where ctdbd is running. This semi-random but there is a bias towards choosing a low numbered node.

ok | healthy
    All nodes that are not disconnected, banned, disabled or unhealthy.

con | connected
    All nodes that are not disconnected.

lvs | lvsmaster
    The current LVS master.

natgw | natgwlist
    The current NAT gateway.

rm | recmaster
    The current recovery master.

OPTIONS

-c
    Execute COMMAND in the current working directory on the specified nodes.

-o <prefix>
    Causes standard output from each node to be saved into a file with name <prefix>.<ip>.

-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.

-n
    Allow nodes to be specified by name rather than node numbers. These nodes don't need to be listed in the nodes file. You can avoid the nodes file entirely by combining this with -f /dev/null.

-f <file>
    Specify an alternative nodes file to use instead of the default. This option overrides the CTDB_NODES_FILE environment variable. See the discussion of /etc/ctdb/nodes in the FILES section for more details.

-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

ENVIRONMENT

CTDB_NODES_FILE
    Name of alternative nodes file to use instead of the default. See the discussion of /etc/ctdb/nodes in the FILES section for more details.

FILES

/etc/ctdb/nodes
    Default file containing a list of each node's IP address or hostname.

    Actually, the default is $CTDB_BASE/nodes, where $CTDB_BASE defaults to /etc/ctdb. If a relative path is given (via the -f option or $CTDB_BASE) and no corresponding file exists relative to the current directory then the file is also searched for in the $CTDB_BASE directory.

/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), http://ctdb.samba.org/

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/.