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</o:shapelayout></xml><![endif]--></head><body lang=DE link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal><span style='mso-fareast-language:EN-US'>I would like to explain you that, but now I am facing another issue. The quota info message appeared „Quota exceeded for cores: Requested 4, but already used 59 of 60 cores“. <o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal>In my version Train is a path called /usr/lib/python2.7/site-packages/nova/openstack with a file called wsgi.py. To be more precise it is the __exit__ function in the ResourceExceptionHandler, which outputs this information message.<span style='mso-fareast-language:EN-US'><o:p></o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal>My question is, where does this function get the information from that the limit of the VCPUs and possibly other resources has been exceeded? I mean the scheduler doesn’t even run. I can’t get it until now. Maybe I need to manipulate the nova-api rather then manipulating the nova-scheduler. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thank you very much and have a nice day!<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Best regards<o:p></o:p></p><p class=MsoNormal>Levon<o:p></o:p></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='mso-fareast-language:EN-US'><o:p> </o:p></span></p><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b>Von:</b> Laurent Dumont <laurentfdumont@gmail.com> <br><b>Gesendet:</b> Mittwoch, 16. Juni 2021 02:55<br><b>An:</b> levonmelikbekjan@yahoo.de<br><b>Cc:</b> Sean Mooney <smooney@redhat.com>; openstack <openstack@lists.openstack.org><br><b>Betreff:</b> Re: AW: AW: Customization of nova-scheduler<o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Out of curiosity, how did you end up implementing your workflow? Through the scheduler or is the logic external to Openstack?<o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Tue, Jun 15, 2021 at 11:48 AM <<a href="mailto:levonmelikbekjan@yahoo.de">levonmelikbekjan@yahoo.de</a>> wrote:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0cm;margin-bottom:5.0pt'><p class=MsoNormal style='margin-bottom:12.0pt'>Hi Sean,<br><br>I am already done with my solution. Everything works as expected! :)<br><br>Thank you for your support. You guys are great.<br><br>Best regards<br>Levon<br><br>-----Ursprüngliche Nachricht-----<br>Von: Sean Mooney <<a href="mailto:smooney@redhat.com" target="_blank">smooney@redhat.com</a>> <br>Gesendet: Dienstag, 15. Juni 2021 16:37<br>An: Stephen Finucane <<a href="mailto:stephenfin@redhat.com" target="_blank">stephenfin@redhat.com</a>>; <a href="mailto:levonmelikbekjan@yahoo.de" target="_blank">levonmelikbekjan@yahoo.de</a>; <a href="mailto:openstack@lists.openstack.org" target="_blank">openstack@lists.openstack.org</a><br>Betreff: Re: AW: AW: Customization of nova-scheduler<br><br>On Tue, 2021-06-15 at 15:18 +0100, Stephen Finucane wrote:<br>> On Thu, 2021-06-10 at 17:21 +0200, <a href="mailto:levonmelikbekjan@yahoo.de" target="_blank">levonmelikbekjan@yahoo.de</a> wrote:<br>> > Hi Stephen,<br>> > <br>> > I'm trying to customize my nova scheduler. However, if I change the <br>> > nova.conf as it is written here <br>> > <a href="https://docs.openstack.org/operations-guide/de/ops-customize-compute" target="_blank">https://docs.openstackorg/operations-guide/de/ops-customize-compute</a><br>> > .html , then my python file cannot be found. How can I configure it <br>> > correctly?<br>> > <br>> > Do you have any idea?<br>> > <br>> > My controller node is running with CENTOS 7. I couldn't install <br>> > devstack because it is only supported for CENTOS 8 version.<br>> <br>> That document is very old. You want [1], which documents how to do <br>> this properly.<br><br>wwell that depend if they acatully want to write ther own filter yes but if they want to replace the scheduler with a new one we recently removed support for that right.<br>previously we had several schduler implemtation like the caching scheduler and that old doc <a href="https://docs.openstack.org/operations-guide/de/ops-customize-compute.html" target="_blank">https://docs.openstack.org/operations-guide/de/ops-customize-compute.html</a><br><br>descibes on how to replace the filter scheduler dirver with an new one.<br>we deprecated it ussuri<br><a href="https://github.com/openstack/nova/commit/6a4cb24d39623930fd240e67d65013803459839d" target="_blank">https://github.com/openstack/nova/commit/6a4cb24d39623930fd240e67d65013803459839d</a><br><br>and you finally removed the extention point in febuary<br><a href="https://github.com/openstack/nova/commit/5aeb3a387494c4559d183d1290db3c92a96dfb90" target="_blank">https://github.com/openstack/nova/commit/5aeb3a387494c4559d183d1290db3c92a96dfb90</a><br>so from wallaby on you can nolonger write an alternitvie schduler implemenation out of tree without reverting that.<br><br>so yes<br><a href="https://docs.openstack.org/nova/latest/user/filter-scheduler#writing-your-own-filter" target="_blank">https://docs.openstack.org/nova/latest/user/filter-scheduler#writing-your-own-filter</a><br>is how you customise schduling now but you cant customise the schduler itself out fo tree anymore.<br><br>> <br>> Hope this helps,<br>> Stephen<br>> <br>> [1]<br>> <a href="https://docs.openstack.org/nova/latest/user/filter-scheduler#writing-y" target="_blank">https://docs.openstack.org/nova/latest/user/filter-scheduler#writing-y</a><br>> our-own-filter<br>> <br>> > Best regards<br>> > Levon<br>> > <br>> > -----Ursprüngliche Nachricht-----<br>> > Von: Stephen Finucane <<a href="mailto:stephenfin@redhat.com" target="_blank">stephenfin@redhat.com</a>><br>> > Gesendet: Montag, 31. Mai 2021 18:21<br>> > An: <a href="mailto:levonmelikbekjan@yahoo.de" target="_blank">levonmelikbekjan@yahoo.de</a>; <a href="mailto:openstack@lists.openstack.org" target="_blank">openstack@lists.openstack.org</a><br>> > Betreff: Re: AW: Customization of nova-scheduler<br>> > <br>> > On Mon, 2021-05-31 at 13:44 +0200, <a href="mailto:levonmelikbekjan@yahoo.de" target="_blank">levonmelikbekjan@yahoo.de</a> wrote:<br>> > > Hello Stephen,<br>> > > <br>> > > I am a student from Germany who is currently working on his <br>> > > bachelor thesis. My job is to build a cloud solution for my <br>> > > university with Openstack. The functionality should include the <br>> > > prioritization of users. So that you can imagine exactly how the <br>> > > whole thing should work, I would like to give you an example<br>> > > <br>> > > Two cases should be solved!<br>> > > <br>> > > Case 1: A user A with a low priority uses a VM from Openstack with <br>> > > half performance of the available host. Then user B comes in with <br>> > > a high priority and needs the full performance of the host for his <br>> > > VM. When creating the VM of user B, the VM of user A should be <br>> > > deleted because there is not enough compute power for user B The <br>> > > VM of user B is successfully created.<br>> > > <br>> > > Case 2: A user A with a low priority uses a VM with half the <br>> > > performance of the available host, then user B comes in with a <br>> > > high priority and needs half of the performance of the host for his VM.<br>> > > When creating the VM of user B, user A should not be deleted, <br>> > > since enough computing power is available for both users.<br>> > > <br>> > > These cases should work for unlimited users. In order to optimize <br>> > > the whole thing, I would like to write a function that precisely <br>> > > calculates all performance components to determine whether enough <br>> > > resources are available for the VM of the high priority user<br>> > <br>> > What you're describing is commonly referred to as "preemptible" or <br>> > "spot"<br>> > instances. This topic has a long, complicated history in nova and <br>> > has yet to be implemented. Searching for "preemptible instances <br>> > openstack" should yield you lots of discussion on the topic along <br>> > with a few proof-of-concept approaches using external services or <br>> > out-of-tree modifications to nova.<br>> > <br>> > > I’m new to Openstack, but I’ve already implemented cloud projects <br>> > > with Microsoft Azure and have solid programming skills. Can you <br>> > > give me a hint where and how I can start?<br>> > <br>> > As hinted above, this is likely to be a very difficult project given <br>> > the fraught history of the idea. I don't want to dissuade you from <br>> > this work but you should be aware of what you're getting into from <br>> > the start. If you're serious about pursuing this, I suggest you <br>> > first do some research on prior art. As noted above, there is lots <br>> > of information on the internet about this. With this research done, <br>> > you'll need to decide whether this is something you want to approach <br>> > within nova itself, via out-of-tree extensions or via a third party <br>> > project. If you're opting for integration with nova, then you'll <br>> > need to think long and hard about how you would design such a system <br>> > and start working on a spec (a design document) outlining your <br>> > proposed solution. Details on how to write a spec are discussed at <br>> > [1]. The only extension points nova offers today are scheduler <br>> > filters and weighers so your options for an out-of-tree extension <br>> > approach will be limited. A third party project will arguably be the <br>> > easiest approach but you will be restricted to talking to nova's <br>> > REST APIs which may limit the design somewhat. This Blazar spec [2] <br>> > could give you some ideas on this approach (assuming it was never <br>> > actually implemented, though it may well have been).<br>> > <br>> > > My university gave me three compute hosts and one control host to <br>> > > implement this solution for the bachelor thesis. I’m currently <br>> > > setting up Openstack and all the services on the control host all <br>> > > by myself to understand all the functionality (sorry for not using<br>> > > Packstack) <span style='font-family:"Segoe UI Emoji",sans-serif'>😉</span>. All my hosts have CentOS 7 and the minimum <br>> > > deployment which I configure is Train.<br>> > > <br>> > > My idea is to work with nova schedulers, because they seem to be <br>> > > interesting for my case. I've found a whole infrastructure <br>> > > description of the provisioning of an instance in Openstack <br>> > > <a href="https://docs.openstack.org/operations-guide/de/_images/provision-a" target="_blank">https://docs.openstack.org/operations-guide/de/_images/provision-a</a><br>> > > n-instance.png<br>> > > .<br>> > > <br>> > > The nova scheduler<br>> > > <a href="https://docs.openstack.org/operations-guide/ops-customize-compute" target="_blank">https://docs.openstack.org/operations-guide/ops-customize-compute</a>.<br>> > > html<br>> > > is the first component, where it is possible to implement <br>> > > functions via Python and the Compute API <br>> > > <a href="https://docs.openstack.org/api-ref/compute/?expanded=show-details-" target="_blank">https://docs.openstack.org/api-ref/compute/?expanded=show-details-</a><br>> > > of-specific-api-version-detail,list-servers-detail<br>> > > to check for active VMs and probably delete them if needed before <br>> > > a successful request for an instantiation can be made.<br>> > > <br>> > > What do you guys think about it? Does it seem like a good starting <br>> > > point for you or is it the wrong approach?<br>> > <br>> > This could potentially work, but I suspect there will be serious <br>> > performance implications with this, particularly at scale. Scheduler <br>> > filters are historically used for simple things like "find me a <br>> > group of hosts that have this metadata attribute I set on my image". <br>> > Making API calls sounds like something that would take significant <br>> > time and therefore slow down the schedule process. You'd also have <br>> > to decide what your heuristic for deciding which VM(s) to delete <br>> > would be, since there's nothing obvious in nova that you could use.<br>> > You could use something as simple as filter extra specs or something <br>> > as complicated as an external service.<br>> > <br>> > This should be lots to get you started. Once again, do make sure <br>> > you're aware of what you're getting yourself into before you start.<br>> > This could get complicated very quickly :)<br>> > <br>> > Cheers,<br>> > Stephen<br>> > <br>> > > I'm very happy to have found you!!! <br>> > > <br>> > > Thank you really much for your time!<br>> > <br>> > <br>> > [1] <a href="https://specs.openstack.org/openstack/nova-specs/readme.html" target="_blank">https://specs.openstack.org/openstack/nova-specs/readme.html</a><br>> > [2]<br>> > <a href="https://specs.openstack.org/openstack/blazar-specs/specs/ussuri/blaz" target="_blank">https://specs.openstack.org/openstack/blazar-specs/specs/ussuri/blaz</a><br>> > ar-preemptible-instances.html<br>> > <br>> > > Best regards<br>> > > Levon<br>> > > <br>> > > -----Ursprüngliche Nachricht-----<br>> > > Von: Stephen Finucane <<a href="mailto:stephenfin@redhat.com" target="_blank">stephenfin@redhat.com</a>><br>> > > Gesendet: Montag, 31. Mai 2021 12:34<br>> > > An: Levon Melikbekjan <<a href="mailto:levonmelikbekjan@yahoo.de" target="_blank">levonmelikbekjan@yahoo.de</a>>; <br>> > > <a href="mailto:openstack@lists.openstack.org" target="_blank">openstack@lists.openstack.org</a><br>> > > Betreff: Re: Customization of nova-scheduler<br>> > > <br>> > > On Wed, 2021-05-26 at 22:46 +0200, Levon Melikbekjan wrote:<br>> > > > Hello Openstack team,<br>> > > > <br>> > > > is it possible to customize the nova-scheduler via Python? If <br>> > > > yes, how?<br>> > > <br>> > > Yes, you can provide your own filters and weighers. This is <br>> > > documented at [1].<br>> > > <br>> > > Hope this helps,<br>> > > Stephen<br>> > > <br>> > > [1]<br>> > > <a href="https://docs.openstack.org/nova/latest/user/filter-scheduler#writi" target="_blank">https://docs.openstack.org/nova/latest/user/filter-scheduler#writi</a><br>> > > ng-y<br>> > > our-own-filter<br>> > > <br>> > > > <br>> > > > Best regards<br>> > > > Levon<br>> > > > <br>> > > <br>> > > <br>> > <br>> > <br>> <br>> <br>> <br><br><br><o:p></o:p></p></blockquote></div></div></body></html>