<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; color: rgb(0, 0, 0); font-size: 14px; font-family: Calibri, sans-serif; "><div><br></div><div><br></div><span id="OLK_SRC_BODY_SECTION"><div style="font-family:Calibri; font-size:11pt; text-align:left; color:black; BORDER-BOTTOM: medium none; BORDER-LEFT: medium none; PADDING-BOTTOM: 0in; PADDING-LEFT: 0in; PADDING-RIGHT: 0in; BORDER-TOP: #b5c4df 1pt solid; BORDER-RIGHT: medium none; PADDING-TOP: 3pt"><span style="font-weight:bold">From: </span> Mike Spreitzer <<a href="mailto:mspreitz@us.ibm.com">mspreitz@us.ibm.com</a>><br><span style="font-weight:bold">Reply-To: </span> OpenStack Development Mailing List <<a href="mailto:openstack-dev@lists.openstack.org">openstack-dev@lists.openstack.org</a>><br><span style="font-weight:bold">Date: </span> Tuesday, September 10, 2013 11:58 PM<br><span style="font-weight:bold">To: </span> OpenStack Development Mailing List <<a href="mailto:openstack-dev@lists.openstack.org">openstack-dev@lists.openstack.org</a>><br><span style="font-weight:bold">Subject: </span> [openstack-dev] [heat] Comments/questions on the instance-group-api-extension blueprint<br></div><div><br></div><div><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><div><font size="2" face="sans-serif">First, I'm a newbie here, wondering: is this the right place for comments/questions on blueprints? Supposing it is...</font></div></div></span><div><br></div><div>[Gary Kotton] Yeah, as Russel said this is the correct place</div><span id="OLK_SRC_BODY_SECTION"><div><div><br><font size="2" face="sans-serif">I am referring to </font><a href="https://blueprints.launchpad.net/nova/+spec/instance-group-api-extension"><font size="2" face="sans-serif">https://blueprints.launchpad.net/nova/+spec/instance-group-api-extension</font></a><br><br><font size="2" face="sans-serif">In my own research group we have experience with a few systems that do something like that, and more (as, indeed, that blueprint explicitly states that it is only the start of a longer roadmap). I would like to highlight a
couple of differences that alarm me. One is the general overlap between groups. I am not saying this is wrong, but as a matter of natural conservatism we have shied away from unnecessary complexities. The only overlap we have done so far is hierarchical
nesting. As the instance-group-api-extension explicitly contemplates groups of groups as a later development, this would cover the overlap that we have needed. On the other hand, we already have multiple "policies" attached to a single group. We have policies
for a variety of concerns, so some can combine completely or somewhat independently. We also have relationships (of various sorts) between groups (as well as between individuals, and between individuals and groups). The policies and relationships, in general,
are not simply names but also have parameters.</font> <br></div></div></span><div><br></div><div>[Gary Kotton] The instance groups was meant to be the first step towards what we had presented in Portland. Please look at the presentation that we gave an this may highlight what the aims were: <a href="https://docs.google.com/presentation/d/1oDXEab2mjxtY-cvufQ8f4cOHM0vIp4iMyfvZPqg8Ivc/edit?usp=sharing">https://docs.google.com/presentation/d/1oDXEab2mjxtY-cvufQ8f4cOHM0vIp4iMyfvZPqg8Ivc/edit?usp=sharing</a>. Sadly for this release we did not manage to get the instance groups through (it was an issue of timing and bad luck). We will hopefully get this though in the first stages of the I cycle and then carry on building on it as it has a huge amount of value for OpenStack. It will be great if you can also participate in the discussions.</div><span id="OLK_SRC_BODY_SECTION"><div><div><br><font size="2" face="sans-serif">Thanks,</font> <br><font size="2" face="sans-serif">Mike</font></div></div></span></body></html>