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<!DOCTYPE refentry
	PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
	"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<refentry id="ping_pong.1">

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

  <refnamediv>
    <refname>ping_pong</refname>
    <refpurpose>measures the ping-pong byte range lock latency</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <cmdsynopsis>
      <command>ping_pong</command>
      <group choice="req">
	<arg choice="plain">-r</arg>
	<arg choice="plain">-w</arg>
	<arg choice="plain">-rw</arg>
      </group>
      <arg>-m</arg>
      <arg>-c</arg>
      <arg choice="req"><replaceable>FILENAME</replaceable></arg>
      <arg choice="req"><replaceable>NUM-LOCKS</replaceable></arg>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>DESCRIPTION</title>
    <para>
      ping_pong measures the byte range lock latency. It is especially
      useful on a cluster of nodes sharing a common lock manager as it
      will give some indication of the lock manager's performance
      under stress.
    </para>

    <para>
      FILENAME is a file on shared storage to use for byte range
      locking tests.
    </para>

    <para>
      NUM-LOCKS is the number of byte range locks, so needs to be
      (strictly) greater than the number of nodes in the cluster.
    </para>
  </refsect1>

  <refsect1>
    <title>OPTIONS</title>

    <variablelist>
      <varlistentry>
	<term>-r</term>
	<listitem>
	  <para>
	    test read performance
	  </para>
	</listitem>
      </varlistentry>

      <varlistentry>
	<term>-w</term>
        <listitem>
          <para>
	    test write performance
	  </para>
        </listitem>
      </varlistentry>

      <varlistentry>
	<term>-m</term>
        <listitem>
          <para>
	    use mmap
	  </para>
        </listitem>
      </varlistentry>

      <varlistentry>
	<term>-c</term>
	<listitem>
          <para>
	    validate the locks
	  </para>
        </listitem>
      </varlistentry>

    </variablelist>
  </refsect1>

  <refsect1>
    <title>EXAMPLES</title>
    <para>
      Testing lock coherence
    </para>
    <screen format="linespecific">
      ping_pong test.dat N
    </screen>

    <para>
      Testing lock coherence with lock validation
    </para>
    <screen format="linespecific">
      ping_pong -c test.dat N
    </screen>

    <para>
      Testing IO coherence
    </para>
    <screen format="linespecific">
      ping_pong -rw test.dat N
    </screen>
  </refsect1>

  <refsect1>
    <title>SEE ALSO</title>
    <para>
      <citerefentry><refentrytitle>ctdb</refentrytitle>
      <manvolnum>7</manvolnum></citerefentry>,

      <ulink url="https://wiki.samba.org/index.php/Ping_pong"/>

    </para>
  </refsect1>

  <refentryinfo>
    <author>
      <contrib>
	This documentation was written by Mathieu Parent
      </contrib>
    </author>

    <copyright>
      <year>2002</year>
      <holder>Andrew Tridgell</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>
