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<p class="MsoNormal">Hi,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">While developing some neutron extensions, one question came up on Cells. Appreciate any comments.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">According to this table in operations guide, a cell shares nova-api and keystone, but does not talk about other services.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I understand from few that Neutron service need to be shared across cells if virtual networks are to be extended to multiple cells. Otherwise, neutron service can be dedicated to each cell.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I guess anybody developing neutron related extensions need to take care both scenarios.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Is that understanding correct? <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Also which deployments are more common – Shared Neutron or dedicated neutrons?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks<br>
Srini<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal" style="margin-bottom:15.0pt"><span class="highlight1"><b><span style="font-size:9.0pt;font-family:"Verdana","sans-serif";color:white">Cell</span></b></span><b><span style="font-size:9.0pt;font-family:"Verdana","sans-serif";color:white">s<o:p></o:p></span></b></p>
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<p class="MsoNormal" style="margin-bottom:15.0pt"><b><span style="font-size:9.0pt;font-family:"Verdana","sans-serif";color:white">Regions<o:p></o:p></span></b></p>
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<p class="MsoNormal" style="margin-bottom:15.0pt"><b><span style="font-size:9.0pt;font-family:"Verdana","sans-serif";color:white">Availability Zones<o:p></o:p></span></b></p>
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<p class="MsoNormal" style="margin-bottom:15.0pt"><b><span style="font-size:9.0pt;font-family:"Verdana","sans-serif";color:white">Host Aggregates<o:p></o:p></span></b></p>
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<p><strong><span style="font-family:"Verdana","sans-serif"">Use when you need</span></strong>
<o:p></o:p></p>
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<p>A single <a href="http://docs.openstack.org/trunk/openstack-ops/content/scaling.html" id="API_endpoint">
<span style="color:black;border:dotted green 1.0pt;padding:0in;background:#FFFFEE;text-decoration:none">API endpoint</span></a> for compute, or you require a second level of scheduling.<o:p></o:p></p>
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<p>Discrete regions with separate API endpoints and no coordination between regions.<o:p></o:p></p>
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<p>Logical separation within your nova deployment for physical isolation or redundancy.<o:p></o:p></p>
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<p>To schedule a group of hosts with common features.<o:p></o:p></p>
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<p><strong><span style="font-family:"Verdana","sans-serif"">Example</span></strong>
<o:p></o:p></p>
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<p>A cloud with multiple sites where you can schedule VMs "anywhere" or on a particular site.<o:p></o:p></p>
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<p>A cloud with multiple sites, where you schedule VMs to a particular site and you want a shared infrastructure.<o:p></o:p></p>
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<p>A single site cloud with equipment fed by separate power supplies.<o:p></o:p></p>
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<p>Scheduling to hosts with trusted hardware support.<o:p></o:p></p>
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<p><strong><span style="font-family:"Verdana","sans-serif"">Overhead</span></strong>
<o:p></o:p></p>
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<p style="margin-left:.5in;text-indent:-.25in;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>A new service, <code>nova-</code><span class="highlight1"><span style="font-family:"Courier New"">cell</span></span><code>s</code><o:p></o:p></p>
<p style="margin-left:.5in;text-indent:-.25in;mso-list:l0 level1 lfo1"><![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>Each <span class="highlight1">cell</span> has a full nova installation except
<code>nova-api</code><o:p></o:p></p>
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<p style="margin-left:.5in;text-indent:-.25in;mso-list:l3 level1 lfo2"><![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>A different API endpoint for every region. <o:p></o:p></p>
<p style="margin-left:.5in;text-indent:-.25in;mso-list:l3 level1 lfo2"><![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>Each region has a full nova installation.<o:p></o:p></p>
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<p style="margin-left:.5in;text-indent:-.25in;mso-list:l2 level1 lfo3"><![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>Configuration changes to nova.conf<o:p></o:p></p>
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<p style="margin-left:.5in;text-indent:-.25in;mso-list:l1 level1 lfo4"><![if !supportLists]><span style="font-family:Symbol"><span style="mso-list:Ignore">·<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]>Configuration changes to nova.conf<o:p></o:p></p>
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<p><strong><span style="font-family:"Verdana","sans-serif"">Shared services</span></strong>
<o:p></o:p></p>
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<p>Keystone<o:p></o:p></p>
<p><code>nova-api</code> <o:p></o:p></p>
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<p>Keystone<o:p></o:p></p>
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<p>Keystone<o:p></o:p></p>
<p>All nova services<o:p></o:p></p>
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<p>Keystone<o:p></o:p></p>
<p>All nova services<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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