Checking node connections (AEN 4.2.0)
=====================================

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    <p>When the AEN nodes cannot communicate with each other as
    intended, it can cause issues with you AEN platform installation.</p>
    <div class="contents local topic" id="contents">
    <ul class="simple">
    <li><a class="reference internal" href="#verifying-server-to-gateway-connectivity" id="id1">Verifying server to gateway connectivity</a></li>
    <li><a class="reference internal" href="#verifying-gateway-to-compute-node-connectivity" id="id2">Verifying gateway to compute node connectivity</a></li>
    <li><a class="reference internal" href="#verifying-gateway-to-server-connectivity" id="id3">Verifying gateway to server connectivity</a></li>
    </ul>
    </div>
    <div class="section" id="verifying-server-to-gateway-connectivity">
    <h2><a class="toc-backref" href="#id1">Verifying server to gateway connectivity</a><a class="headerlink" href="#verifying-server-to-gateway-connectivity" title="Permalink to this headline">¶</a></h2>
    <ol class="arabic">
    <li><p class="first">On the server, in the AEN navigation bar, click Admin to
    open the Admin Settings page.</p>
    </li>
    <li><p class="first">In the <strong>Site Admin</strong> menu, select Data Centers:</p>
    <div class="figure">
    <img alt="../../../../_images/ae-notebooks/4.2.0/aen-admin-admin_datacenter1.png" src="../../../../_images/ae-notebooks/4.2.0/aen-admin-admin_datacenter1.png" />
    </div>
    <div class="line-block">
    <div class="line"><br /></div>
    </div>
    </li>
    <li><p class="first">For each data center in the list, check connectivity from the
    server to that gateway.</p>
    <p>EXAMPLE: The gateway in this example is
    <code class="docutils literal"><span class="pre">http://gateway.example.com:8089</span></code>:</p>
    <div class="highlight-bash"><div class="highlight"><pre><span></span>root@server <span class="c1"># curl --connect-timeout 5 http://gateway.example.com:8089 &gt; /dev/null</span>
    </pre></div>
    </div>
    </li>
    </ol>
    </div>
    <div class="section" id="verifying-gateway-to-compute-node-connectivity">
    <h2><a class="toc-backref" href="#id2">Verifying gateway to compute node connectivity</a><a class="headerlink" href="#verifying-gateway-to-compute-node-connectivity" title="Permalink to this headline">¶</a></h2>
    <ol class="arabic">
    <li><p class="first">On the server, in the AEN navigation bar, click Admin to open
    the Admin Settings page.</p>
    </li>
    <li><p class="first">In the <strong>Providers</strong> menu, select Enterprise Resources:</p>
    <div class="figure">
    <img alt="../../../../_images/ae-notebooks/4.2.0/aen-admin-admin_enterpriseresources.png" src="../../../../_images/ae-notebooks/4.2.0/aen-admin-admin_enterpriseresources.png" />
    </div>
    <div class="line-block">
    <div class="line"><br /></div>
    </div>
    </li>
    <li><p class="first">Open each compute node in the Resources section.</p>
    </li>
    <li><p class="first">Verify that the contents of the URL field begin with either
    <code class="docutils literal"><span class="pre">http</span></code> or <code class="docutils literal"><span class="pre">https</span></code>.</p>
    <div class="figure">
    <img alt="../../../../_images/ae-notebooks/4.2.0/aen-admin-admin_er_editresource.png" src="../../../../_images/ae-notebooks/4.2.0/aen-admin-admin_er_editresource.png" />
    </div>
    <div class="line-block">
    <div class="line"><br /></div>
    </div>
    </li>
    <li><p class="first">Check connectivity to that URL from the corresponding gateway.</p>
    <p>EXAMPLE: The gateway in this example is
    <code class="docutils literal"><span class="pre">http://gateway.example.com:8089</span></code>:</p>
    <div class="highlight-bash"><div class="highlight"><pre><span></span>root@gateway <span class="c1"># curl --connect-timeout 5 http://compute.example.com:5002 &gt; /dev/null</span>
    </pre></div>
    </div>
    </li>
    </ol>
    </div>
    <div class="section" id="verifying-gateway-to-server-connectivity">
    <h2><a class="toc-backref" href="#id3">Verifying gateway to server connectivity</a><a class="headerlink" href="#verifying-gateway-to-server-connectivity" title="Permalink to this headline">¶</a></h2>
    <p>The gateway-to-server path is used by the gateway configuration
    command <code class="docutils literal"><span class="pre">wk-gateway-configure</span></code>.</p>
    <ol class="arabic">
    <li><p class="first">Verify that the gateway is linked to the correct server in the
    configuration file.</p>
    </li>
    <li><p class="first">Verify that the full server URL is specified.</p>
    </li>
    <li><p class="first">Check connectivity to the server:</p>
    <div class="highlight-bash"><div class="highlight"><pre><span></span>root@gateway <span class="c1"># grep WAKARI_SERVER /opt/wakari/wakari-gateway/etc/wakari/wk-gateway-config.json</span>
      <span class="s2">&quot;WAKARI_SERVER&quot;</span>: <span class="s2">&quot;http://wakari.example.com&quot;</span>,

    root@gateway <span class="c1"># curl --connect-timeout 5 http://wakari.example.com &gt; /dev/null</span>
    root@gateway <span class="c1"># curl --connect-timeout 5 http://error.example.com &gt; /dev/null</span>
    curl: <span class="o">(</span><span class="m">7</span><span class="o">)</span> Failed to connect to error.example.com port <span class="m">80</span>: Connection refused
    </pre></div>
    </div>
    </li>
    <li><p class="first">If a connection fails:</p>
    <ol class="arabic">
    <li><p class="first">Ensure that gateways (data centers) and compute nodes
    (Enterprise Resources) are correctly configured on the
    server.</p>
    </li>
    <li><p class="first">Verify that processes are listening on the configured ports:</p>
    <div class="highlight-bash"><div class="highlight"><pre><span></span>$ sudo netstat -nplt
    Active Internet connections <span class="o">(</span>only servers<span class="o">)</span>
    Proto Recv-Q Send-Q Local Address   Foreign Address State  PID/Program
    tcp        <span class="m">0</span>      <span class="m">0</span> *:80            *:*             LISTEN <span class="m">26409</span>/nginx
    tcp        <span class="m">0</span>      <span class="m">0</span> *:22            *:*             LISTEN <span class="m">986</span>/sshd
    tcp        <span class="m">0</span>      <span class="m">0</span> <span class="m">127</span>.0.0.1:25    *:*             LISTEN <span class="m">1063</span>/master
    tcp        <span class="m">0</span>      <span class="m">0</span> *:5000          *:*             LISTEN <span class="m">26192</span>/python
    tcp        <span class="m">0</span>      <span class="m">0</span> <span class="m">127</span>.0.0.1:27017 *:*             LISTEN <span class="m">29261</span>/mongod
    tcp        <span class="m">0</span>      <span class="m">0</span> *:22            *:*             LISTEN <span class="m">986</span>/sshd
    tcp        <span class="m">0</span>      <span class="m">0</span> <span class="m">127</span>.0.0.1:25    *:*             LISTEN <span class="m">1063</span>/master
    </pre></div>
    </div>
    </li>
    <li><p class="first">Check the firewall setting and logs on both hosts to ensure
    that packets are not being blocked or discarded.</p>
    </li>
    </ol>
    </li>
    </ol>
    </div>
