<div dir="ltr"><p style="margin:0in;font-family:Calibri;font-size:11pt">Hi all,</p><p style="margin:0in;font-family:Calibri;font-size:11pt">I've been researching the Neutron project as a part of work on Openstack rolling upgrades, my primary assignments included testing if there is no VM access downtime when performing upgrade.</p><p style="margin:0in;font-family:Calibri;font-size:11pt"> </p><p style="margin:0in;font-family:Calibri;font-size:11pt">Are you aware of any issues that are present in Liberty release of Neutron, that may cause the VM access downtime and may stop ops to pick up newest versions of code?</p><p style="margin:0in;font-family:Calibri;font-size:11pt"> </p><p style="margin:0in;font-family:Calibri;font-size:11pt">When talking about no VM access downtime during upgrade, the sensitive operations are:</p><ol type="1" style="margin-left:0.375in;direction:ltr;margin-top:0in;margin-bottom:0in;font-family:Calibri;font-size:11pt"><li value="1" style="margin-left:15px;margin-top:0px;margin-bottom:0px;vertical-align:middle"><span style="font-size:11pt">ensure that even after neutron services is shutoff/uninstalled, the traffic can go into the VM</span></li><li style="margin-left:15px;margin-top:0px;margin-bottom:0px;vertical-align:middle"><span style="font-size:11pt">take care on neutron services startup/installation that existing configuration is preserved (routing tables, forwarding entries and security rules)</span></li><li style="margin-left:15px;margin-top:0px;margin-bottom:0px;vertical-align:middle"><span style="font-size:11pt">the underlying network technologies (OVS, linux bridges etc.) is working without distraction when upgrading neutron code: no dropping table flows or applying the traffic rules to drop the packages</span></li></ol><p style="margin:0in;font-family:Calibri;font-size:11pt"> </p><p style="margin:0in;font-family:Calibri;font-size:11pt">To be compatible between different versions of service talking to each other, the important areas are:</p><ol type="1" style="margin-left:0.375in;direction:ltr;margin-top:0in;margin-bottom:0in;font-family:Calibri;font-size:11pt"><li value="1" lang="pl" style="margin-left:15px;margin-top:0px;margin-bottom:0px;vertical-align:middle"><span style="font-size:11pt">RPC API versioning</span></li><li style="margin-left:15px;margin-top:0px;margin-bottom:0px;vertical-align:middle"><span style="font-size:11pt">Objects exchanged between services via RPC</span></li><li style="margin-left:15px;margin-top:0px;margin-bottom:0px;vertical-align:middle"><span style="font-size:11pt">Database schema<span style="font-size:14.6666669845581px"> (bp [2])</span> and data migration</span></li></ol><p style="margin:0in;font-family:Calibri;font-size:11pt"> </p><p style="margin:0in;font-family:Calibri;font-size:11pt">I have researched the ML2 plugin with ovs agent, including the neutron-ovs-agent, dhcp-server, l3-agent, neutron-server.</p><p style="margin:0in;font-family:Calibri;font-size:11pt">One of the VM access downtime during upgrade is addressed in [1], removing the flows in ovs after neutron agent restarts.</p><p style="margin:0in;font-family:Calibri;font-size:11pt"> </p><p style="margin:0in;font-family:Calibri;font-size:11pt">Is Neutron ready to be upgradable with minimal downtime of services and no VM access downtime?</p><p style="margin:0in;font-family:Calibri;font-size:11pt">Are there any guidelines on using the oslo versionobjects and its priority in Liberty cycle?</p><p style="margin:0in;font-family:Calibri;font-size:11pt">Are there use-cases written down when talking about Neutron upgrades? </p><p style="margin:0in;font-family:Calibri;font-size:11pt"> </p><p style="font-size:12.8000001907349px;margin:0in;font-family:Calibri"><span style="font-size:11pt">[1]</span><span style="font-size:12pt"> </span><a href="https://bugs.launchpad.net/neutron/+bug/1383674" target="_blank"><span style="font-size:11pt">https://bugs.launchpad.net/neutron/+bug/1383674</span></a></p><p style="font-size:12.8000001907349px;margin:0in;font-family:Calibri"><span style="font-size:11pt">[2]</span><span style="font-size:12pt"> </span><a href="https://review.openstack.org/#/c/192937/3/specs/liberty/online-schema-migrations.rst" target="_blank"><span style="font-size:11pt">https://review.openstack.org/#/c/192937/3/specs/liberty/online-schema-migrations.rst</span></a></p><p style="margin:0in;font-family:Calibri;font-size:11pt"> </p><p lang="pl" style="margin:0in;font-family:Calibri;font-size:11pt">Regards,</p><p lang="pl" style="margin:0in;font-family:Calibri;font-size:11pt"></p><p lang="pl" style="margin:0in;font-family:Calibri;font-size:11pt">Artur Korzeniewski</p></div>