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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Hi,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Deployment of VM takes some resources – at least you must load/copy the base image and boot the machine. Both of these operations consumes resources. This might
not seem as a problem for deployment of single VM. But deploying tens or hundreds of VMs at single moment can kill your hypervisors/underlying storage (worst case) or at least slow down running VMs – what might kill some apps running in them/against them.
So yes, high load really matters.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Ondra<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> users-bounces@lists.opennebula.org [mailto:users-bounces@lists.opennebula.org]
<b>On Behalf Of </b>Andrea Gardiman<br>
<b>Sent:</b> Friday, March 07, 2014 4:30 PM<br>
<b>To:</b> users@lists.opennebula.org<br>
<b>Subject:</b> Re: [one-users] scheduler interval<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p>Ok, but I don't understand why it works like a pull model instead of push. Is so because of a too high load matter or only because the initial architectural decision was to work like that and now it is still so?<o:p></o:p></p>
<p>What would be the drawbacks if were the core,immediately every time a request arrive, tell to the scheduler to schedule that request?<o:p></o:p></p>
<p>My question comes because I'm working on improving the deployment time of VMs for my master thesis, and I understood that I can choose to deploy VMs little by little, or immediately as they come but I can't see the cases in which deploy VMs little by little
would be better that process them immediately.<o:p></o:p></p>
<p>Thanks a lot,<o:p></o:p></p>
<p> Andrea Gardiman.<o:p></o:p></p>
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<p class="MsoNormal">On Mar 7, 2014 10:58 AM, "Carlos Martín Sánchez" <<a href="mailto:cmartin@opennebula.org">cmartin@opennebula.org</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal">Hi,<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Thu, Mar 6, 2014 at 1:30 PM, Andrea Gardiman <<a href="mailto:andreagardiman@gmail.com" target="_blank">andreagardiman@gmail.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal">Dear all,<o:p></o:p></p>
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<p class="MsoNormal">I do not understand the usefulness of the scheduler parameter "SCHED_INTERVAL". Why the scheduler act as a periodic task and have to wait a fixed period to schedule all the pending jobs instead of to be event-driven and schedule immediately
a request?<o:p></o:p></p>
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<p class="MsoNormal">What are the benefits and the drawbacks, besides the wait?<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Thanks a lot,<o:p></o:p></p>
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<p class="MsoNormal"> Andrea Gardiman.<o:p></o:p></p>
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<p class="MsoNormal"> <o:p></o:p></p>
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<p class="MsoNormal">The scheduler is a separate daemon. So it polls the core periodically to look for pending VMs.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">The usefulness of the SCHED_INTERVAL is that, combined with the other config parameters [1] MAX_DISPATCH and MAX_HOST, allows you to configure a "buffer" to deploy VMs little by little, or immediately as they come.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Regards<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">[1] <a href="http://docs.opennebula.org/stable/administration/references/schg.html" target="_blank">
http://docs.opennebula.org/stable/administration/references/schg.html</a><o:p></o:p></p>
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<o:p></o:p></p>
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<p class="MsoNormal">--<o:p></o:p></p>
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<p class="MsoNormal">Carlos Martín, MSc<br>
Project Engineer<o:p></o:p></p>
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<p class="MsoNormal">OpenNebula - Flexible Enterprise Cloud Made Simple<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#888888"><a href="http://www.OpenNebula.org" target="_blank">www.OpenNebula.org</a> |
<a href="mailto:cmartin@opennebula.org" target="_blank">cmartin@opennebula.org</a> |
<a href="http://twitter.com/opennebula" target="_blank">@OpenNebula</a></span><o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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