<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;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
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.shorttext
{mso-style-name:short_text;}
span.hps
{mso-style-name:hps;}
span.EmailStyle19
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
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-US" link="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I run high-availability squid servers on virtual machines although not yet in OpenNebula.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">It can be done with very high availability.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I am not familiar with Ubuntu Server 12.04 but if it has libvirt 0.9.7 or better, and you are
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Using KVM hypervisor, you should be able to use the cpu-pinning and numa-aware features of libvirt to pin<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">each virtual machine to a given physical cpu. That will beat the migration issue you are seeing now.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">With Xen hypervisor you can (and should) also pin.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I think if you beat the cpu and memory pinning problem you will be OK.<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">However, you did not say what network topology you are using for your virtual machine, and what kind of virtual network drivers,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">That is important too. Also—is your squid cache mostly disk-resident or mostly RAM-resident? If the former then the virtual disk drivers matter too, a lot.<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">Steve Timm<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"><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>Erico Augusto Cavalcanti Guedes<br>
<b>Sent:</b> Saturday, August 25, 2012 6:33 PM<br>
<b>To:</b> users@lists.opennebula.org<br>
<b>Subject:</b> [one-users] Very high unavailable service<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Dears,<br>
<br>
I 'm running Squid Web Cache Proxy server on Ubuntu Server 12.04 VMs (kernel 3.2.0-23-generic-pae), OpenNebula 3.4.<br>
My private cloud is composed by one frontend and three nodes. VMs are running on that 3 nodes, initially one by node.<br>
Outside cloud, there are 2 hosts, one working as web clients and another as web server, using Web Polygraph Benchmakring Tool.<br>
<br>
The goal of tests is stress Squid cache running on VMs.<br>
When same test is executed outside the cloud, using the three nodes as Physical Machines, there are 100% of cache service availability.<br>
Nevertheless, when cache service is provided by VMs, nothing better than 45% of service availability is reached.<br>
Web clients do not receive responses from squid when it is running on VMs in 55% of the time.<br>
<br>
I have monitored load average of VMs and PMs where VMs are been executed. First load average field reaches 15 after some hours of tests on VMs, and 3 on physical machines.<br>
<span class="hps"><span lang="EN">Furthermore, t</span></span>here is a set of processes, called migration/X, that are champions in CPU TIME when VMs are in execution. A sample:<br>
<br>
<span style="font-family:"Courier New"">top - 20:01:38 up 1 day, 3:36, 1 user, load average: 5.50, 5.47, 4.20<br>
<br>
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ TIME COMMAND
<br>
13 root RT 0 0 0 0 S 0 0.0 408:27.25 408:27 migration/2
<br>
8 root RT 0 0 0 0 S 0 0.0 404:13.63 404:13 migration/1
<br>
6 root RT 0 0 0 0 S 0 0.0 401:36.78 401:36 migration/0
<br>
17 root RT 0 0 0 0 S 0 0.0 400:59.10 400:59 migration/3 <br>
</span><br>
<br>
<span class="hps"><span lang="EN">It isn't possible to offer</span></span><span lang="EN"> web cache service
<span class="hps">via</span> <span class="hps">VMs in the way</span> <span class="hps">
the service</span> <span class="hps">is behaving</span>, with so small availability.<br>
<br>
So, my questions:<br>
<br>
1</span>. Does anybody has experienced a similar problem of unresponsive service? (Whatever service).<br>
<span lang="EN">2. How to state the bootleneck that is overloading the system, so that it can be
<span class="hps">minimized?</span></span><br>
<br>
Thanks a lot,<br>
<br>
Erico.<o:p></o:p></p>
</div>
</body>
</html>