I am going to close this bug, partly because it is so old without any updates, but also because there have been a number of improvements over the past few cycles wrt scaling that this is probably not as much an issue any more.
** Changed in: neutron Status: Confirmed => Won't Fix -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to neutron. https://bugs.launchpad.net/bugs/1526855 Title: VMs fail to get metadata in large scale environments Status in neutron: Won't Fix Bug description: In large scale environments, instances can fail to get their metadata. Tests were performed in a 100 compute node environment creating 4000 vms. 15-20 vms will fail all 20 metadata request attempts. This has been reproduced multiple times with similar results. All of the vms successfully obtain a private ip and are pingable but a small number of vms fail to be reachable via ssh. Increasing the number of metadata request attempts in a Cirros test image shows that the metadata requests eventually will succeed. It just takes a long time in some cases. Below is a list of instance uuids I collected from one test and the number of metadata request attempts it took to be successful. These tests were performed using stable/liberty with a small number of patches cherry-picked from Mitaka which were intended to improve performance. 705c3582-f39b-482d-9a6e-d78bc033d3e7 5 27f93574-19fe-4b88-ad6e-c518022ef66a 2 ff668db8-196e-4ec3-82d9-f7ab5a302305 57 b3f97acb-6374-4406-9474-7bacfc3486cd 42 80c19187-7c19-4adc-ad3a-51342f00d799 51 071f60d5-2a9a-4448-b14b-9016c9eee4eb 47 d39f336e-0fb4-4934-b835-e791661d60f1 36 a5627d9f-fd2d-48b0-ada2-f519a97849ee 5 3c24145e-8e11-4e79-8618-fca0416ea030 41 a36ab8fd-4e53-4265-a2bf-6945ac5d8811 46 a9400361-8941-4f03-b11d-0940b5499b4b 37 7449efbd-1df6-4fcc-88d5-e4e355ae7963 24 45c6a108-c18b-4284-9ede-3e5f8d7851be 30 fbe7c6fc-6aec-464c-87b7-0800836f7754 7 cb5a3a49-45b9-40de-8c62-903bee1925f4 37 0c7151ce-79dc-4d55-a617-7f4182cb2194 14 0f1c24a0-3b97-4d56-8feb-b30d67cf6852 44 8c359465-198f-4654-84bb-f334f0400d58 10 b3a5a3df-28c4-40c3-adba-856a0fcbd29e 55 38ee6525-441e-4640-a998-ad89b8d3f8be 2 07ecde16-c274-481e-8169-4febb15c7273 48 f77cd7aa-89e2-4d2c-a89f-e19ff430e5a4 31 b9acdba1-1794-4fa8-bbe3-ffb94f86d19b 3 30824aa6-3df5-4a43-a701-dd33da7f704f 13 5216ffc0-4a8d-4a3e-a4e3-5473b96ca47b 40 999512ff-70e3-4cfd-9cb4-c5788a02fee6 4 To manage notifications about this bug go to: https://bugs.launchpad.net/neutron/+bug/1526855/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : yahoo-eng-team@lists.launchpad.net Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp