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    <p>I think that may be a red herring related to rsyslog?  When we
      most recently rebooted the MDT, this is the log (still on the box,
      not on the log server):</p>
    <p>May  3 14:24:22 asimov kernel: LNet: HW CPU cores: 12,
      npartitions: 4<br>
      May  3 14:24:30 asimov kernel: LNet: Added LNI 10.7.17.8@o2ib
      [8/256/0/180]<br>
    </p>
    And lctl list_nids gives it once:<br>
    <br>
    [root@asimov ~]# lctl list_nids<br>
    10.7.17.8@o2ib<br>
    <br>
    Jessica<br>
    <br>
    <div class="moz-cite-prefix">On 5/19/17 10:13 AM, Jeff Johnson
      wrote:<br>
    </div>
    <blockquote
cite="mid:CAFCYAsdK0NvbzVVBNNzJh+WT=dbyiT18XbMVdLoVu7R0iBjTMg@mail.gmail.com"
      type="cite">
      <div>Jessica,</div>
      <div><br>
      </div>
      <div>You are getting a NID registering twice. Doug noticed and
        pointed it out. I'd look to see if that is one machine doing
        something twice or two machines with the same NID.</div>
      <div><br>
      </div>
      <div>--Jeff </div>
      <div><br>
        <div class="gmail_quote">
          <div>On Fri, May 19, 2017 at 05:58 Ms. Megan Larko <<a
              moz-do-not-send="true" href="mailto:dobsonunit@gmail.com">dobsonunit@gmail.com</a>>
            wrote:<br>
          </div>
          <blockquote class="gmail_quote" style="margin:0 0 0
            .8ex;border-left:1px #ccc solid;padding-left:1ex">
            <div>
              <div>Greetings Jessica,</div>
              <div><br>
              </div>
              <div>I'm not sure I am correctly understanding the
                behavior "robinhood activity floods the MDT".   The
                robinhood program as you (and I) are using it is
                consuming the MDT CHANGELOG via a reader_id which was
                assigned when the CHANGELOG was enabled on the MDT.  
                You can check the MDS for these readers via "lctl
                get_param mdd.*.changelog_users".  Each CHANGELOG reader
                must either be consumed by a process or destroyed
                otherwise the CHANGELOG will grow until it consumes
                sufficient space to stop the MDT from functioning
                correctly.  So robinhood should consume and then clear
                the CHANGELOG via this reader_id.  This implementation
                of robinhood is actually a rather light-weight process
                as far as the MDS is concerned.   The load issues I
                encountered were on the robinhood server itself which is
                a separate server from the Lustre MGS/MDS server.</div>
              <div><br>
              </div>
              <div>Just curious, have you checked for multiple
                reader_id's on your MDS for this Lustre file system?</div>
              <div><br>
              </div>
              <div>P.S. My robinhood configuration file is using
                nb_threads = 8, just for a data point.</div>
              <div><br>
              </div>
              <div>Cheers,</div>
              <div>megan</div>
            </div>
            <div class="gmail_extra"><br>
              <div class="gmail_quote">On Thu, May 18, 2017 at 2:36 PM,
                Jessica Otey <span><<a moz-do-not-send="true"
                    href="mailto:jotey@nrao.edu" target="_blank">jotey@nrao.edu</a>></span>
                wrote:<br>
                <blockquote class="gmail_quote" style="margin:0 0 0
                  .8ex;border-left:1px #ccc solid;padding-left:1ex">
                  <div text="#000000" bgcolor="#FFFFFF">
                    <p>Hi Megan,<br>
                    </p>
                    <p>Thanks for your input. We use percona, a drop-in
                      replacement for mysql... The robinhood activity
                      floods the MDT, but it does not seem to produce
                      any excessive load on the robinhood box...</p>
                    <p>Anyway, FWIW...<br>
                    </p>
                    <p>~]# mysql --version<br>
                      mysql  Ver 14.14 Distrib 5.5.54-38.6, for Linux
                      (x86_64) using readline 5.1<br>
                    </p>
                    <p>Product:         robinhood<br>
                      Version:         3.0-1<br>
                      Build:           2017-03-13 10:29:26<br>
                      <br>
                      Compilation switches:<br>
                          Lustre filesystems<br>
                          Lustre Version: 2.5<br>
                          Address entries by FID<br>
                          MDT Changelogs supported<br>
                      <br>
                      Database binding: MySQL<br>
                    </p>
                    <p>RPM: robinhood-lustre-3.0-1.lustre2.5.el6.x86_64</p>
                    Lustre rpms:<br>
                    <p>lustre-client-2.5.5-2.6.32_642.15.1.el6.x86_64_g22a210f.x86_64<br>
lustre-client-modules-2.5.5-2.6.32_642.15.1.el6.x86_64_g22a210f.x86_64<br>
                    </p>
                    <br>
                    <div
                      class="m_8402669983453079809m_-8956838098082579714moz-cite-prefix">On
                      5/18/17 11:55 AM, Ms. Megan Larko wrote:<br>
                    </div>
                    <blockquote type="cite">
                      <div>
                        <div>With regards to (WRT) Subject "Robinhood
                          exhausting RPC resources against 2.5.5 
                           lustre file systems", what version of
                          robinhood and what version of MySQL
                          database?   I mention this because I have been
                          working with robinhood-3.0-0.rc1 and initially
                          MySQL-5.5.32 and Lustre 2.5.42.1 on
                          kernel-2.6.32-573 and had issues in which the
                          robinhood server consumed more than the total
                          amount of 32 CPU cores on the robinhood server
                          (with 128 G RAM) and would functionally hang
                          the robinhood server.   The issue was solved
                          for me by changing to MySQL-5.6.35.   It was
                          the "sort" command in robinhood that was not
                          working well with the MySQL-5.5.32.</div>
                        <div><br>
                        </div>
                        <div>Cheers,</div>
                        <div>megan</div>
                      </div>
                      <div class="gmail_extra"><br>
                      </div>
                    </blockquote>
                    <br>
                  </div>
                </blockquote>
              </div>
              <br>
            </div>
            _______________________________________________<br>
            lustre-discuss mailing list<br>
            <a moz-do-not-send="true"
              href="mailto:lustre-discuss@lists.lustre.org"
              target="_blank">lustre-discuss@lists.lustre.org</a><br>
            <a moz-do-not-send="true"
              href="http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org"
              rel="noreferrer" target="_blank">http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org</a><br>
          </blockquote>
        </div>
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      <div dir="ltr">-- <br>
      </div>
      <div data-smartmail="gmail_signature">
        <div dir="ltr">------------------------------<br>
          Jeff Johnson<br>
          Co-Founder<br>
          Aeon Computing<br>
          <br>
          <a moz-do-not-send="true"
            href="mailto:jeff.johnson@aeoncomputing.com" target="_blank">jeff.johnson@aeoncomputing.com</a><br>
          <a moz-do-not-send="true" href="http://www.aeoncomputing.com"
            target="_blank">www.aeoncomputing.com</a><br>
          t: 858-412-3810 x1001   f: 858-412-3845<br>
          m: 619-204-9061<br>
          <br>
          4170 Morena Boulevard, Suite D - San Diego, CA 92117
          <div><br>
          </div>
          <div>High-Performance Computing / Lustre Filesystems /
            Scale-out Storage</div>
        </div>
      </div>
    </blockquote>
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