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<!DOCTYPE chapter SYSTEM "chapter.dtd">

<chapter>
  <header>
    <copyright>
      <year>2004</year><year>2010</year>
      <holder>Ericsson AB. All Rights Reserved.</holder>
    </copyright>
    <legalnotice>
      The contents of this file are subject to the Erlang Public License,
      Version 1.1, (the "License"); you may not use this file except in
      compliance with the License. You should have received a copy of the
      Erlang Public License along with this software. If not, it can be
      retrieved online at http://www.erlang.org/.

      Software distributed under the License is distributed on an "AS IS"
      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
      the License for the specific language governing rights and limitations
      under the License.

    </legalnotice>

    <title>OS_Mon Release Notes</title>
    <prepared>otp_appnotes</prepared>
    <docno>nil</docno>
    <date>nil</date>
    <rev>nil</rev>
    <file>notes.xml</file>
  </header>
  <p>This document describes the changes made to the OS_Mon application.</p>

<section><title>Os_Mon 2.2.5</title>

    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    Cleanups suggested by tidier and modernization of types
	    and specs.</p>
          <p>
	    Own Id: OTP-8455</p>
        </item>
      </list>
    </section>

</section>

<section><title>Os_Mon 2.2.4</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    Memsup did not read memory correctly on MaxOSX
	    Snowleopard. This has now been corrected. (Thanks to Joel
	    Reymont)</p>
          <p>
	    Own Id: OTP-8211</p>
        </item>
        <item>
          <p>
	    Removed unused code in <c>cpu_sup.erl</c>.</p>
          <p>
	    Own Id: OTP-8226</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    The documentation is now built with open source tools
	    (xsltproc and fop) that exists on most platforms. One
	    visible change is that the frames are removed.</p>
          <p>
	    Own Id: OTP-8201</p>
        </item>
      </list>
    </section>

</section>

<section><title>Os_Mon 2.2.3</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    A missing define in <c>memsup.c</c> caused a build error
	    on IRIX machines. This has now been fixed.</p>
          <p>
	    Own Id: OTP-8094</p>
        </item>
      </list>
    </section>

</section>

<section><title>Os_Mon 2.2.2</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    disksup:get_disk_data/0 returned disk volume in bytes
	    instead of kbytes as stated in the documentation. The
	    problem occurred on Windows only and is now corrected.</p>
          <p>
	    *** POTENTIAL INCOMPATIBILITY ***</p>
          <p>
	    Own Id: OTP-7741</p>
        </item>
      </list>
    </section>

</section>

<section><title>Os_Mon 2.2.1</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>An error in <c>memsup</c> could cause <c>os_mon</c> to
	    report erroneous memory values on windows for ranges of
	    memory between 2GB and 4GB. This have now been fixed.</p>
          <p>
	    Own Id: OTP-7944</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
	    <p>Added support for dragonfly OS.</p>
          <p>
	    Own Id: OTP-7938</p>
        </item>
      </list>
    </section>

</section>

<section><title>Os_Mon 2.2</title>

    <section><title>Improvements and New Features</title>
      <list>
        <item>
	    <p>The copyright notices have been updated.</p>
          <p>
	    Own Id: OTP-7851</p>
        </item>
      </list>
    </section>

</section>

<section><title>Os_Mon 2.1.8</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>A problem with <c>OTP-OS-MON-MIB.mib</c> for 64-bit
	    environments has now been fixed. The mib has been
	    extended with 64-bit memory retrieval
	    counterparts.</p><p>In addition, a new function
	    <c>get_os_wordsize/0</c> has been added in the
	    <c>memsup</c> module</p>
          <p>
	    Own Id: OTP-7441</p>
        </item>
        <item>
	    <p>An error in <c>memsup.c</c> caused the compilation to
	    crash on bsd environments. This has now been fixed.</p>
          <p>
	    Own Id: OTP-7558</p>
        </item>
      </list>
    </section>

</section>

<section><title>Os_Mon 2.1.7</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
	    <p>Fixed a build error that occurred on NetBSD (Thanks to
	    Per Hedeland and Raphael Langerhorst)</p>
          <p>
	    Own Id: OTP-7505</p>
        </item>
      </list>
    </section>


    <section><title>Improvements and New Features</title>
      <list>
        <item>
	    <p> Memory information in
	    <c>memsup:get_system_memory_data/0</c> now has additional
	    entries in its property list for linux.</p>
          <p>
	    Own Id: OTP-7409 Aux Id: seq10984 </p>
        </item>
      </list>
    </section>

</section>

<section><title>Os_Mon 2.1.6</title>

    <section><title>Fixed Bugs and Malfunctions</title>
      <list>
        <item>
          <p>
	    System information retrieval on darwin platforms with
	    environments locales not conforming to the C locale
	    caused an error in <c>cpu_sup</c> resulting in process
	    termination.</p>
          <p>
	    Own Id: OTP-7320</p>
        </item>
      </list>
    </section>

</section>

<section><title>Os_Mon 2.1.5</title>
    <section><title>Improvements and New Features</title>
      <list>
        <item>
          <p>
	    CPU utilization, on linux, is now measured via a port
	    program instead of os:cmd in erlang. This should enhance
	    performance.</p>
          <p>
	    Own Id: OTP-7108 Aux Id: OTP-6935 </p>
        </item>
      </list>
    </section>
</section>

  <section><title>Os_Mon 2.1.3</title>
    <section><title>Improvements and New Features</title>
      <list type="bulleted">
        <item>
          <p>
	    Extended memsup memory probing on linux to use a port
	    program to probe memory usage. This is faster then the
	    previous implementation.</p>
          <p>
	    Own Id: OTP-6860 Aux Id: seq10616 </p>
        </item>
      </list>
    </section>
   </section>


  <section>
    <title>Os_Mon 2.1.2.1</title>

    <section>
      <title>Improvements and New Features</title>
      <list type="bulleted">
        <item>
          <p>Minor Makefile changes.</p>
          <p>Own Id: OTP-6689</p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>OS_Mon 2.1.2</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>When the <c>memsup_system_only</c> flag was set to
            <c>true</c>, a <c>badmatch</c> exception occurred in the
            function <c>os_mon_mib:get_load/1</c>.</p>
          <p>Own Id: OTP-6351 Aux Id: seq10517</p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>OS_Mon 2.1.1</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>Did not build on Mac OS X.</p>
          <p>Added support for IRIX. (Thanks to Michel Urvoy and
            Daniel Solaz.)</p>
          <p>Own Id: OTP-6136</p>
        </item>
      </list>
    </section>

    <section>
      <title>Improvements and New Features</title>
      <list type="bulleted">
        <item>
          <p><c>disksup</c>: Now using <c>round(T*100)</c> instead of
            <c>trunc(T*100)</c> when setting the threshold value
            given a float <c>T</c>.</p>
          <p>Own Id: OTP-6153</p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>Os_Mon 2.1</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>In 2.0, a call to <c>alarm_handler:get_alarms/0</c> was
            introduced in <c>memsup</c> and <c>disksup</c>. This will
            lead to problems if the default <c>alarm_handler</c>
            event handler is not used, however, and the call has now
            been removed. (Thanks to Serge Aleynikov for pointing
            this out.)</p>
          <p>Own Id: OTP-6029</p>
        </item>
        <item>
          <p>A bug that in rare cases caused <c>cpu_sup</c> to crash
            has been corrected.</p>
          <p>Own Id: OTP-6102 Aux Id: seq10312 </p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>OS_Mon 2.0</title>
    <p>A note on backwards compatibility: The behaviour of OS_Mon 2.0 is
      backwards compatible under normal operation, but has changed
      somewhat in error situations: The services do not terminate
      and the API functions do not raise exceptions in all cases where
      they did before. Also, in the case where a service does terminate,
      the exit reason may be different. See below for details.</p>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>A call to a OS_Mon service (cpu_sup, disksup, ...) when
            OS_Mon is not running, or when the service is not
            available for the OS, or when the service is not started,
            will no longer result in an exception. Instead a warning
            is issued via error_logger and a dummy value is returned,
            which one is specified in the man pages for the
            respective service.</p>
          <p>The reason is that it should not be necessary for a
            service to be started on each and every node of a
            distributed Erlang system for the OS-MON-MIB and other
            OS_Mon users to work properly.</p>
          <p>Own Id: OTP-4332 Aux Id: seq7358 </p>
        </item>
        <item>
          <p>References to the obsolete EVA application in
            OTP-OS-MON-MIB has been removed.</p>
          <p>Own Id: OTP-5699</p>
        </item>
        <item>
          <p>Setting the option <c>memsup_system_only</c> to
            <c>true</c> did not work, but would crash the
            <c>memsup</c> process.</p>
          <p>Own Id: OTP-5890 Aux Id: seq10185 </p>
        </item>
        <item>
          <p><c>cpu_sup:nprocs/0</c> returned 0 on FreeBsd.</p>
          <p>Own Id: OTP-5901</p>
        </item>
        <item>
          <p>If the OS_Mon service <c>disksup</c> or <c>memsup</c> was
            restarted, the same alarm could be set twice. Also, set
            alarms were not cleared when the application was stopped.</p>
          <p>Own Id: OTP-5910</p>
        </item>
      </list>
    </section>

    <section>
      <title>Improvements and New Features</title>
      <list type="bulleted">
        <item>
          <p>Thresholds and time intervals in <c>disksup</c> and
            <c>memsup</c> are now configurable in run-time.</p>
          <p>Own Id: OTP-4246 Aux Id: Seq7230 </p>
        </item>
        <item>
          <p><c>memsup</c> can now handle systems with more than 4GB
            of RAM.</p>
          <p>Own Id: OTP-5800 Aux Id: seq10130 </p>
        </item>
        <item>
          <p>The entire OS_Mon application (code and documentation)
            has been reviewed and consequently updated with the goal
            to make the application more robust, homogeneous and
            easier to configure.</p>
          <p>The behaviour under normal operation is backwards
            compatible. However, recoverable errors now no longer
            terminate the affected service (and thus possible the
            entire application), instead <c>error_logger</c> is used
            to warn the user if/when such errors occurs. Also, in the
            case of unrecoverable errors, the services have been made
            more homogeneous with respect to behavior and exit
            reasons. See below for more information and refer to the
            man pages for details.</p>
          <p>Port handling has been unified, meaning that if a port
            program sends garbage or unexpectedly dies, this is now
            handled the same way by all OS_Mon services, namely
            immediate process termination with the exit reason
            <c>{port_error,Garbage}</c> or <c>{port_died,Reason}</c>,
            respectively.</p>
          <p>Application configuration parameter handling has been
            unified. Bad parameter values are no longer silently
            ignored (<c>disksup</c>) or cause application termination
            (<c>memsup</c>, <c>os_sup</c>). Instead a warning is
            issued and the default value for the parameter is used.
            Also, some cases where a bad parameter value accidentally
            could be accepted have been corrected.</p>
          <p>Message handling has been unified. Unknown
            (<c>gen_server-</c>) calls cause process termination,
            whereas unknown casts and messages are now ignored by all
            OS_Mon services.</p>
          <p>Own Id: OTP-5897</p>
        </item>
        <item>
          <p>The following changes have been made to the <c>os_sup</c>
            service:</p>
          <p>It is now available on Windows, using <c>nteventlog</c>
            as backend.</p>
          <p>On Solaris, enabling the service (that is, installing a
            new configuration file for <c>syslogd</c> etc.) can now
            be done outside the <c>os_sup</c> process. The reason for
            this is that the Erlang emulator should normally not be
            run with <c>root</c> privileges, as is otherwise
            required. The new application configuration parameter
            <c>os_sup_config</c> must be set to <c>false</c>.</p>
          <p>Also, <c>os_sup</c> can now be configured using a new
            configuration parameter <c>os_sup_mfa</c> to call an
            arbitrary Erlang function when a message is received from
            the OS.</p>
          <p>Own Id: OTP-5925</p>
        </item>
        <item>
          <p>The <c>memsup</c> service has been rewritten, replacing
            the supervised <c>memsup_helper</c> with a linked help
            process. This gives the <c>memsup</c> process more
            control and prevents a situation where it gets out of
            synch with the received memory data and thus possibly
            returns erroneous results.</p>
          <p>Own Id: OTP-5927</p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>OS_Mon 1.8.1</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p><c>cpu_sup:util/0</c> failed with error reason
            <c>negative_diff</c> when called the first time on a
            machine (hw) that had been up for a very long time.</p>
          <p>Own Id: OTP-5869 Aux Id: seq10166</p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>OS_Mon 1.8</title>

    <section>
      <title>Improvements and New Features</title>
      <list type="bulleted">
        <item>
          <p>The memsup part of the OS_Mon application has been made
            more stable. If there are (possibly temporary) problems
            collecting memory data, the interface functions
            (<c>get_memory_data/0</c>,
            <c>get_system_memory_data/0</c>) now do not fail, but
            return the previously collected value, if any, or a dummy
            value otherwise. Also, a warning message is printed.</p>
          <p>*** POTENTIAL INCOMPATIBILITY ***</p>
          <p>Own Id: OTP-5798</p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>OS_Mon 1.7.4</title>

    <section>
      <title>Fixed Bugs and Malfunctions</title>
      <list type="bulleted">
        <item>
          <p>Corrected several problems in the error handling/error
            recovery (especially when OS_Mon is starting up).</p>
          <p>Own Id: OTP-5559</p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>OS_Mon 1.7.3</title>

    <section>
      <title>Improvements and New Features</title>
      <list type="bulleted">
        <item>
          <p><c>memsup.c</c> will now compile on OpenBSD. (Thanks to
            Geoff White and Jay Nelson.)</p>
          <p>The <c>disksup</c> and <c>cpu_sup</c> modules now work on
            Mac OS X (tested on Mac OS 10.3.8).</p>
          <p>The <c>memsup</c> module should now work on Linux 2.6.* as
            well as on older Linuxes. (<c>/proc/meminfo</c> has
            slightly different formats in different releases of
            Linux.)</p>
          <p>Own Id: OTP-5421            <br></br>

            Aux Id: OTP-5194, OTP-5228, OTP-5291 </p>
        </item>
      </list>
    </section>
  </section>

  <section>
    <title>OS_Mon 1.7.2</title>
    <p>This version is identical with 1.7.</p>
  </section>
</chapter>

