Jay, Huiba, Chris, Solly, Zhiyan, and everybody else, I am so excited that two of the proposals: Image Upload Plugin( http://summit.openstack.org/cfp/details/353) and Data transfer service Plugin(http://summit.openstack.org/cfp/details/352) have been merged together and scheduled in the coming design summit. If you show up in Atlanta, please come this session( http://junodesignsummit.sched.org/event/c00119362c07e4cb203d1c4053add187) and start our discussion, on Wednesday, May 14 • 11:50am - 12:30pm.
I will propose a common image transfer library for all the OpenStack projects to to upload and download the images. If it is approved, with this library, Huiba, you can feel free to implement the transfer protocols you like. Best wishes, Vincent Hou (侯胜博) Staff Software Engineer, Open Standards and Open Source Team, Emerging Technology Institute, IBM China Software Development Lab Tel: 86-10-82450778 Fax: 86-10-82453660 Notes ID: Sheng Bo Hou/China/IBM@IBMCN E-mail: sb...@cn.ibm.com Address:3F Ring, Building 28 Zhongguancun Software Park, 8 Dongbeiwang West Road, Haidian District, Beijing, P.R.C.100193 地址:北京市海淀区东北旺西路8号中关村软件园28号楼环宇大厦3层 邮编：100193 Sheng Bo Hou/China/IBM@IBMCN 2014/04/27 22:33 Please respond to "OpenStack Development Mailing List \(not for usage questions\)" <openstack-dev@lists.openstack.org> To "OpenStack Development Mailing List \(not for usage questions\)" <openstack-dev@lists.openstack.org>, cc Subject Re: [openstack-dev] [Nova][blueprint] Accelerate the booting process of a number of vms via VMThunder I have done a little test for the image download and upload. I created an API for the image access, containing copyFrom and sendTo. I moved the image download and upload code from XenApi into the implementation for Http with some modifications, and the code worked for libvirt as well. copyFrom means to download the image and return the image data, and different hypervisors can choose to save it in a file or import it to the datastore; sendTo is used to upload the image and the image data is passed in as a parameter. I also did an investigation about how each hypervisor is doing the image upload and download. For the download: libvirt, hyper-v and baremetal use the code image_service.download to download the image and save it into a file. vmwareapi uses the code image_service.download to download the image and import it into the datastore. XenAPi uses image_service.download to download the image for VHD image. For the upload: They use image_service.upload to upload the image. I think we can conclude that it is possible to have a common image transfer library with different implementations for different protocols. This is a small demo code for the library: https://review.openstack.org/#/c/90601/(Jay, is it close to the library as you mentioned?). I just replaced the upload and download part with the http implementation for the imageapi and it worked fine. Best wishes, Vincent Hou (侯胜博) Staff Software Engineer, Open Standards and Open Source Team, Emerging Technology Institute, IBM China Software Development Lab Tel: 86-10-82450778 Fax: 86-10-82453660 Notes ID: Sheng Bo Hou/China/IBM@IBMCN E-mail: sb...@cn.ibm.com Address:3F Ring, Building 28 Zhongguancun Software Park, 8 Dongbeiwang West Road, Haidian District, Beijing, P.R.C.100193 地址:北京市海淀区东北旺西路8号中关村软件园28号楼环宇大厦3层 邮编：100193 Solly Ross <sr...@redhat.com> 2014/04/25 01:46 Please respond to "OpenStack Development Mailing List \(not for usage questions\)" <openstack-dev@lists.openstack.org> To "OpenStack Development Mailing List (not for usage questions)" <openstack-dev@lists.openstack.org>, cc Subject Re: [openstack-dev] [Nova][blueprint] Accelerate the booting process of a number of vms via VMThunder Something to be aware of when planing an image transfer library is that individual drivers might have optimized support for image transfer in certain cases (especially when dealing with transferring between different formats, like raw to qcow2, etc). This builds on what Christopher was saying -- there's actually a reason why we have code for each driver. While having a common image copying library would be nice, I think a better way to do it would be to have some sort of library composed of building blocks, such that each driver could make use of common functionality while still tailoring the operation to the quirks of the particular drivers. Best Regards, Solly Ross ----- Original Message ----- From: "Christopher Lefelhocz" <christopher.lefel...@rackspace.com> To: "OpenStack Development Mailing List (not for usage questions)" <openstack-dev@lists.openstack.org> Sent: Thursday, April 24, 2014 11:17:41 AM Subject: Re: [openstack-dev] [Nova][blueprint] Accelerate the booting process of a number of vms via VMThunder Apologies for coming to this discussion late... On 4/22/14 6:21 PM, "Jay Pipes" <jaypi...@gmail.com> wrote: > >Right, a good solution would allow for some flexibility via multiple >transfer drivers. +1. In particular I don't think this discussion should degenerate into zero-copy vs. pre caching. I see both as possible solutions depending on deployer/environment needs. > >> Jay Pipes has suggested we figure out a blueprint for a separate >> library dedicated to the data(byte) transfer, which may be put in oslo >> and used by any projects in need (Hoping Jay can come in:-)). Huiba, >> Zhiyan, everyone else, do you think we come up with a blueprint about >> the data transfer in oslo can work? > >Yes, so I believe the most appropriate solution is to create a library >-- in oslo or a standalone library like taskflow -- that would offer a >simple byte streaming library that could be used by nova.image to expose >a neat and clean task-based API. > >Right now, there is a bunch of random image transfer code spread >throughout nova.image and in each of the virt drivers there seems to be >different re-implementations of similar functionality. I propose we >clean all that up and have nova.image expose an API so that a virt >driver could do something like this: > >from nova.image import api as image_api > >... > >task = image_api.copy(from_path_or_uri, to_path_or_uri) ># do some other work >copy_task_result = task.wait() > >Within nova.image.api.copy(), we would use the aforementioned transfer >library to move the image bits from the source to the destination using >the most appropriate method. If I understand correctly, we'll create some common library around this. It would be good to understand the details a bit better. I've thought a bit about this issue. The one area that I get stuck at is providing a common set of downloads which work across drivers effectively. Part of the reason there are a bunch or random image transfers is historical, but also because performance was already a problem. Examples include: transferring to compute first then copying to dom0 causing performance issues, needs in some drivers to download image completely to validate prior to putting in place, etc. It may be easy to say we'll push most of this to the dom0, but I know for Xen our python stack is somewhat limited so that may be an issue. By the way we've been working on proposing a simpler image pre caching system/strategy. It focuses specifically on the image caching portion of this discussion. For those interested, see the nova-spec https://review.openstack.org/#/c/85792. We'd like to leverage whatever optimized image download strategy is available. Christopher _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
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