path: root/ctdb/doc/onnode.1.xml

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<refentry id="onnode.1">

  <refmeta>
    <refentrytitle>onnode</refentrytitle>
    <manvolnum>1</manvolnum>
    <refmiscinfo class="source">ctdb</refmiscinfo>
    <refmiscinfo class="manual">CTDB - clustered TDB database</refmiscinfo>
  </refmeta>

  <refnamediv>
    <refname>onnode</refname>
    <refpurpose>run commands on CTDB cluster nodes</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <cmdsynopsis>
      <command>onnode</command>
      <arg rep="repeat"><replaceable>OPTION</replaceable></arg>
      <arg choice="req"><replaceable>NODES</replaceable></arg>
      <arg choice="req"><replaceable>COMMAND</replaceable></arg>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>DESCRIPTION</title>
    <para>
      onnode is a utility to run commands on a specific node of a CTDB
      cluster, or on all nodes.
    </para>
    <para>
      <replaceable>NODES</replaceable> specifies which node(s) to run
      a command on.  See section <citetitle>NODES
      SPECIFICATION</citetitle> for details.
    </para>
    <para>
      <replaceable>COMMAND</replaceable> can be any shell command. The
      onnode utility uses ssh or rsh to connect to the remote nodes
      and run the command.
    </para>
  </refsect1>

  <refsect1>
    <title>OPTIONS</title>

    <variablelist>
      <varlistentry><term>-c</term>
        <listitem>
          <para>
            Execute COMMAND in the current working directory on the
            specified nodes.
	  </para>
        </listitem>
      </varlistentry>

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

      <varlistentry><term>-i</term>
        <listitem>
          <para>
	    Keep standard input open, allowing data to be piped to
	    onnode.  Normally onnode closes stdin to avoid surprises
	    when scripting.  Note that this option is ignored when
	    using <option>-p</option> or if <envar>SSH</envar> is set
	    to anything other than "ssh".
	  </para>
        </listitem>
      </varlistentry>

      <varlistentry><term>-n</term>
        <listitem>
          <para>
            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 <code>-f /dev/null</code>.
	  </para>
        </listitem>
      </varlistentry>

      <varlistentry><term>-o <parameter>PREFIX</parameter></term>
        <listitem>
          <para>
	    Causes standard output from each node to be saved into a
	    file with name PREFIX.<replaceable>IP</replaceable>.
	  </para>
        </listitem>
      </varlistentry>

      <varlistentry><term>-p</term>
        <listitem>
          <para>
            Run COMMAND in parallel on the specified nodes.  The
            default is to run COMMAND sequentially on each node.
	  </para>
        </listitem>
      </varlistentry>

      <varlistentry><term>-P</term>
        <listitem>
          <para>
            Push files to nodes.  Names of files to push are specified
            rather than the usual command.  Quoting is fragile/broken
            - filenames with whitespace in them are not supported.
	  </para>
        </listitem>
      </varlistentry>

      <varlistentry><term>-q</term>
        <listitem>
          <para>
            Do not print node addresses.  Normally, onnode prints
            informational node addresses if more than one node is
            specified.  This overrides -v.
	  </para>
        </listitem>
      </varlistentry>

      <varlistentry><term>-v</term>
        <listitem>
          <para>
            Print node addresses even if only one node is specified.
            Normally, onnode prints informational node addresses when
            more than one node is specified.
	  </para>
        </listitem>
      </varlistentry>

      <varlistentry><term>-h, --help</term>
        <listitem>
          <para>
            Show a short usage guide.
	  </para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>NODES SPECIFICATION</title>

    <para>
      Nodes can be specified via numeric node numbers (from 0 to N-1)
      or mnemonics.  Multiple nodes are specified using 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.
    </para>

    <para>
      The following mnemonics are available:
    </para>

    <variablelist>
      <varlistentry><term>all</term>
        <listitem>
          <para>
            All nodes.
	  </para>
        </listitem>
      </varlistentry>
      <varlistentry><term>any</term>
        <listitem>
          <para>
             A node where ctdbd is running.  This semi-random but
             there is a bias towards choosing a low numbered node.
	  </para>
        </listitem>
      </varlistentry>
      <varlistentry><term>ok | healthy</term>
        <listitem>
          <para>
            All nodes that are not disconnected, banned, disabled or
            unhealthy.
	  </para>
        </listitem>
      </varlistentry>
      <varlistentry><term>con | connected</term>
        <listitem>
          <para>
            All nodes that are not disconnected.
	  </para>
        </listitem>
      </varlistentry>
      <varlistentry><term>lvs | lvsmaster</term>
        <listitem>
          <para>
            The current LVS master.
	  </para>
        </listitem>
      </varlistentry>
      <varlistentry><term>natgw | natgwlist</term>
        <listitem>
          <para>
            The current NAT gateway.
	  </para>
        </listitem>
      </varlistentry>
      <varlistentry><term>rm | recmaster</term>
        <listitem>
          <para>
            The current recovery master.
	  </para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>EXAMPLES</title>

    <para>
      The following command would show the process ID of ctdbd on all nodes
    </para>
    <screen format="linespecific">
      onnode all ctdb getpid
    </screen>

    <para>
      The following command would show the last 5 lines of log on each
      node, preceded by the node's hostname
    </para>
    <screen format="linespecific">
      onnode all "hostname; tail -5 /var/log/log.ctdb"
    </screen>

    <para>
      The following command would restart the ctdb service on all
      nodes, in parallel.
    </para>
    <screen format="linespecific">
      onnode -p all service ctdb restart
    </screen>

    <para>
      The following command would run ./foo in the current working
      directory, in parallel, on nodes 0, 2, 3 and 4.
    </para>
    <screen format="linespecific">
      onnode -c -p 0,2-4 ./foo
    </screen>
  </refsect1>

  <refsect1>
    <title>ENVIRONMENT</title>

    <variablelist>
      <varlistentry><term><envar>CTDB_BASE</envar></term>
        <listitem>
          <para>
	    Directory containing CTDB configuration files.  The
	    default is <filename>/etc/ctdb</filename>.
	  </para>
        </listitem>
      </varlistentry>

      <varlistentry><term><envar>CTDB_NODES_FILE</envar></term>
        <listitem>
          <para>
	    Name of alternative nodes file to use instead of the
	    default.  See the <citetitle>FILES</citetitle> section for
	    more details.
	  </para>
        </listitem>
      </varlistentry>

    </variablelist>
  </refsect1>

  <refsect1>
    <title>FILES</title>

    <variablelist>
      <varlistentry><term><filename>/etc/ctdb/nodes</filename></term>
        <listitem>
          <para>
            Default file containing a list of each node's IP address
            or hostname.
	  </para>
	  <para>
	    Actually, the default is
	    <filename>$CTDB_BASE/nodes</filename>, where
	    <envar>CTDB_BASE</envar> defaults to
	    <filename>/etc/ctdb</filename>.  If a relative path is
	    given (via the -f option or <envar>CTDB_BASE</envar>) and
	    no corresponding file exists relative to the current
	    directory then the file is also searched for in the
	    <filename>$CTDB_BASE</filename> directory.
	  </para>
        </listitem>
      </varlistentry>

      <varlistentry><term><filename>/etc/ctdb/onnode.conf</filename></term>
        <listitem>
          <para>
            If this file exists it is sourced by onnode.  The main
            purpose is to allow the administrator to set
            <envar>SSH</envar> 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.
	  </para>
        </listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>SEE ALSO</title>

    <para>
      <citerefentry><refentrytitle>ctdb</refentrytitle>
      <manvolnum>7</manvolnum></citerefentry>,

      <ulink url="http://ctdb.samba.org/"/>
    </para>
  </refsect1>

  <refentryinfo>
    <author>
      <contrib>
	This documentation was written by
	Andrew Tridgell,
	Martin Schwenke
      </contrib>
    </author>

    <copyright>
      <year>2007</year>
      <holder>Andrew Tridgell</holder>
      <holder>Ronnie Sahlberg</holder>
    </copyright>
    <copyright>
      <year>2008</year>
      <holder>Martin Schwenke</holder>
    </copyright>
    <legalnotice>
      <para>
	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.
      </para>
      <para>
	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.
      </para>
      <para>
	You should have received a copy of the GNU General Public
	License along with this program; if not, see
	<ulink url="http://www.gnu.org/licenses"/>.
      </para>
    </legalnotice>
  </refentryinfo>

</refentry>