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<p class="MsoNormal" align="left" style="text-align:left;text-autospace:none"><span lang="EN-US" style="font-size:14.0pt;color:black">Pacemaker provides the high availability for openstack infrastructure.
<o:p></o:p></span></p>
<p class="MsoNormal" align="left" style="text-align:left;text-autospace:none"><span lang="EN-US" style="font-size:14.0pt;color:black">We'd like to deliver the vm-level HA to improve the business continuity with openstack.<o:p></o:p></span></p>
<p class="MsoNormal" align="left" style="text-align:left;text-autospace:none"><span lang="EN-US" style="font-size:14.0pt;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal" align="left" style="text-align:left;text-autospace:none"><span lang="EN-US" style="font-size:14.0pt;color:black">Besides host failure, Our HA mechanism can detect and report host isolation, network partition as well as ha agent down.
<o:p></o:p></span></p>
<p class="MsoNormal" align="left" style="text-align:left;text-autospace:none"><span lang="EN-US" style="font-size:14.0pt;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal" align="left" style="text-align:left;text-autospace:none"><span lang="EN-US" style="font-size:14.0pt;color:black">Ha agent is placed on every node of the system. The master agent is elected automatically on system startup and others will
be regarded as the slave. <o:p></o:p></span></p>
<p class="MsoNormal" align="left" style="text-align:left;text-autospace:none"><span lang="EN-US" style="font-size:14.0pt;color:black">For the host states detection, the ha agents communicates through the storage subsystem as well as over the management network.
Multiple communication paths enable better assessment of the health of the host. On host failure, the master agent selects the candidate hosts and calls the slave ha agents. The slave ha agents talk to the nova compute to restart the virtual machine. The master
agent reacts to ha agent down by reporting to the administrator. During the network partition or host isolation event, the HA mechanism will not interrupt the virtual machines and just keep them running.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:14.0pt;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:14.0pt;color:black">For the virtual machine detection, the ha agents relies on nova compute for the information about virtual machines.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:14.0pt;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:14.0pt;color:black">Please let me know your comments on this.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:14.0pt;color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:14.0pt;color:black">Regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:14.0pt;color:black">Jenny</span><span lang="EN-US"><o:p></o:p></span></p>
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