<div dir="ltr"><br><div class="gmail_extra"><br><div class="gmail_quote">On Fri, May 22, 2015 at 8:48 AM, Amrith Kumar <span dir="ltr"><<a href="mailto:amrith@tesora.com" target="_blank">amrith@tesora.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">I’m posting this to the mailing list to summarize my notes from a meeting at 5pm yesterday at Summit relative to Zaqar and lightweight multi-tenant messaging and how it may be applicable
to a number of projects.<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">I’ll begin by saying these are not ‘minutes’ of a meeting, merely my notes and observations after the meeting and how they relate specifically to Trove. I don’t claim to speak for
Trove, other contributors to Trove, other projects who were at the meeting, for zaqar, etc., etc.,
<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">After the meeting I think I have a slightly better understanding of what Zaqar is but I am still not entirely sure. As best as I can tell, it is a lightweight, keystone authenticated,
multi-tenant messaging system. I am still a little troubled that of the many people in the room who were knowledgeable of zaqar, there appeared to be some disagreement on how best to describe or explain the project.</span></p></div></div></blockquote><div><br></div><div>If we cannot agree on how to explain zaqar, how can projects even think about adopting it?</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div lang="EN-US" link="#0563C1" vlink="#954F72"><div><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New""><u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">I learned that users of zaqar can authenticate with keystone and then interact with zaqar, and pass messages using it. I learned also that zaqar is spelt with a ‘q’ that is not followed
by a ‘u’. i.e. it isn’t zaquar as I had thought it was.<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">It became clear that the underlying transport in zaqar is not based on an existing AMQP service, rather zaqar is a “from the ground up” implementation. This scares me (a lot).<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">I gather there is currently no oslo.messaging integration with zaqar; for Trove to use zaqar we would have to either (a) abandon oslo.messaging and use zaqar, or (b) build in smarts
within Trove to determine at run time whether we are using zaqar or o.m and implement code in Trove to handle the differences between them if any.<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">It wasn’t clear to me after the meeting what differences there may be with Trove; one which was alluded to was the inability to do a synchronous (call()) style message and the statement
was that this was something that “could be built into a driver”.<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">It wasn’t clear to me what scale zaqar has been run at and whether anyone has in fact deployed and run zaqar at scale, and whether it has been battle hardened the way a service like
RabbitMQ has. While I hear from many that RabbitMQ is a nightmare to scale and manage, I realize that it does in fact have a long history of deployments at scale.<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">We discussed some of the assumptions being made in the conversation relative to the security of the various parties to the communication on the existing rabbit message queue and at
the conclusion of the meeting I believe we left things as below.<u></u><u></u></span></p>
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<p><u></u><span style="font-size:10.0pt;font-family:"Courier New""><span>(a)</span></span><u></u><span style="font-size:10.0pt;font-family:"Courier New"">Zaqar
would be more appealing if it had a simple oslo.messaging driver and an easier path to integration by client projects like Trove. The rip-and-replace option put a certain damper on the enthusiasm<u></u><u></u></span></p>
<p><u></u><span style="font-size:10.0pt;font-family:"Courier New""><span>(b)</span></span><u></u><span style="font-size:10.0pt;font-family:"Courier New"">Even
with an o.m integration, the incremental benefits that zaqar brought were diminished by the fact that one would still have to operate an AMQP (RabbitMQ) service for the rest of the infrastructure message passing needs unless and until all projects decide to
abandon RabbitMQ in favor of zaqar<u></u><u></u></span></p>
<p><u></u><span style="font-size:10.0pt;font-family:"Courier New""><span>(c)</span></span><u></u><span style="font-size:10.0pt;font-family:"Courier New"">At
this time it is likely that there is no net benefit to a project like Trove in integrating with zaqar given that the upside is likely limited, the downside(s) that we know of are significant, and there is a significant unknown risk.<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">My thanks to the folks from zaqar for having the session, I certainly learnt a lot more about the project, and about openstack.<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">Let me conclude where I began, by saying the preceding is not a ‘minutes of the meeting’, merely my notes from the meeting.<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">Thanks,<span class="HOEnZb"><font color="#888888"><u></u><u></u></font></span></span></p><span class="HOEnZb"><font color="#888888">
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Courier New"">-amrith<u></u><u></u></span></p>
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