<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<meta name="Generator" content="Microsoft Word 14 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-IN" link="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoNormal">Hi Devs,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Problem Statement: Performance and storage efficiency of shelving/unshelving instance booted from image is far worse than instance booted from volume.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">When you unshelve hundreds of instances at the same time, instance spawning time varies and it mainly depends on the size of the instance snapshot and<o:p></o:p></p>
<p class="MsoNormal">the network speed between glance and nova servers.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">If you have configured file store (shared storage) as a backend in Glance for storing images/snapshots, then it's possible to improve the performance of<o:p></o:p></p>
<p class="MsoNormal">unshelve instance dramatically by configuring nova.image.download.FileTransfer in nova. In this case, it simply copies the instance snapshot as if it is<o:p></o:p></p>
<p class="MsoNormal">stored on the local filesystem of the compute node. But then again in this case, it is observed the network traffic between shared storage servers and<o:p></o:p></p>
<p class="MsoNormal">nova increases enormously resulting in slow spawning of the instances.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I would like to gather some thoughts about how we can improve the performance of unshelve api (booted from image only) in terms of downloading large<o:p></o:p></p>
<p class="MsoNormal">size instance snapshots from glance.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I have proposed a nova-specs [1] to address this performance issue. Please take a look at it.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">During the last nova mid-cycle summit, <a href="https://review.openstack.org/#/q/owner:mikal%2540stillhq.com+status:open,n,z" title="Michael Still <mikal@stillhq.com>">
<span style="color:windowtext;text-decoration:none">Michael Still</span></a> has suggested alternative solutions to tackle this issue.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Storage solutions like ceph (Software based) and NetApp (Hardare based) support exposing images from glance to nova-compute and cinder-volume with<o:p></o:p></p>
<p class="MsoNormal">copy in write feature. This way there will be no need to download the instance snapshot and unshelve api will be pretty faster than getting it<o:p></o:p></p>
<p class="MsoNormal">from glance.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Do you think the above performance issue should be handled in the OpenStack software as described in nova-specs [1] or storage solutions like<o:p></o:p></p>
<p class="MsoNormal">ceph/NetApp should be used in production environment? Apart from ceph/NetApp solutions, are there any other options available in the market.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">[1] https://review.openstack.org/#/c/135387/<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thank You,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Abhishek Kekane<o:p></o:p></p>
</div>
<br clear="both">
______________________________________________________________________<BR>
Disclaimer: This email and any attachments are sent in strictest confidence<BR>
for the sole use of the addressee and may contain legally privileged,<BR>
confidential, and proprietary data. If you are not the intended recipient,<BR>
please advise the sender by replying promptly to this email and then delete<BR>
and destroy this email and any attachments without any further use, copying<BR>
or forwarding.<BR>
</body>
</html>