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    <p>Container Launchers,</p>
    <p>Please find the notes below and at</p>
    <p> 
<a class="moz-txt-link-freetext" href="https://halldweb.jlab.org/wiki/index.php/GlueX_Containers_Meeting,_March_30,_2018">https://halldweb.jlab.org/wiki/index.php/GlueX_Containers_Meeting,_March_30,_2018</a></p>
    <p>  -- Mark</p>
    <p>________________</p>
    <p>
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          <h1 id="firstHeading" class="firstHeading" lang="en"><span
              dir="auto">GlueX Containers Meeting, March 30, 2018</span></h1>
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              <h3><span class="mw-headline" id="Notes">Notes</span></h3>
              <p>Present: Sean Dobbs, Mark Ito, Thomas Britton, Beni
                Zihlmann, Zisis Papandreau, David Lawrence, Richard
                Jones
              </p>
              <ul>
                <li> Atlas and CMS and OSG et al. designed a grid to do
                  raw data reconstruction.
                  <ul>
                    <li> MC was not considered a problem</li>
                    <li> The tiered system has as a component the raw
                      data distribution system</li>
                    <li> software and databases were staged as "image
                      files"</li>
                  </ul>
                </li>
                <li> XROOTD
                  <ul>
                    <li> originally developed at SLAC</li>
                    <li> redirector: directory service, contains meta
                      data (file locations)</li>
                    <li> on the local host open a file just like a local
                      file except file name is replaced with a URL like
                      root://<name of catalog><IP name of
                      redirector><file name>, triggers an open
                      over network</li>
                    <li> redirector refers opener to site, a data
                      connection is opened on site, data streamed over
                      connection</li>
                    <li> our bandwidth requirements should be OK</li>
                    <li> David: at NERSC, 64 threads on a single node,
                      reconstruction, 4 MB/s read rate</li>
                    <li> there is a caching system, if everything is
                      mostly working cache, is not heavily used</li>
                  </ul>
                </li>
                <li> UConn demo system
                  <ul>
                    <li> redirector service started</li>
                    <li> 50 servers, each serving a few files</li>
                    <li> 10 Gb pipe</li>
                  </ul>
                </li>
                <li> Client side responsibilities
                  <ul>
                    <li> download and build XROOTD</li>
                    <li> set-up ld_preload[?]</li>
                    <li> open calls get intercepted and redirected to
                      XROOTD system</li>
                  </ul>
                </li>
                <li> Sean has also messed with setting up an XROOTD
                  server</li>
                <li> David mentioned the XROOTD idea to Amber Boehnlein,
                  she seems supportive
                  <ul>
                    <li> Consensus that it would be best if
                      infrastructure supported at JLab on the submit
                      host</li>
                    <li> Could be used for both raw data and random
                      trigger files</li>
                    <li> Richard and Thomas will work on staging random
                      triggers on UConn demo system</li>
                  </ul>
                </li>
                <li> David: Chip may allow Physics to use 5% of future
                  LQCD KNL cluster</li>
                <li> David: planning for summer campaign at NERSC,
                  reconstruction
                  <ul>
                    <li> Sean: candidates for off-site resource
                      campaigns:
                      <ul>
                        <li> ρ and ω yield measurements with 10 or 20
                          files per run</li>
                        <li> 2017 data: 2 periods, low intensity and
                          high intensity</li>
                        <li> 2018 data: 4 periods</li>
                      </ul>
                    </li>
                  </ul>
                </li>
              </ul>
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          <li id="lastmod"> This page was last modified on 7 April 2018,
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