Re: [openstack-dev] [neutron] HA of dhcp agents?
Hi Noel, On 22 October 2014 01:57, Noel Burton-Krahn n...@pistoncloud.com wrote: Hi Armando, Sort of... but what happens when the second one dies? You mean, you lost both (all) agents? In this case, yes you'd need to resurrect the agents or move the networks to another available agent. If one DHCP agent dies, I need to be able to start a new DHCP agent on another host and take over from it. As far as I can tell right now, when one DHCP agent dies, another doesn't take up the slack. I am not sure I fully understand the failure mode you are trying to address. The DHCP agents can work in an active-active configuration, so if you have N agents assigned per network, all of them should be able to address DHCP traffic. If this is not your experience, ie. one agent dies and DHCP is no longer served on the network by any other agent, then there might be some other problem going on. I have the same problem wit L3 agents by the way, that's next on my list -- Noel On Tue, Oct 21, 2014 at 12:52 PM, Armando M. arma...@gmail.com wrote: As far as I can tell when you specify: dhcp_agents_per_network = X 1 The server binds the network to all the agents (up to X), which means that you have multiple instances of dnsmasq serving dhcp requests at the same time. If one agent dies, there is no fail-over needed per se, as the other agent will continue to server dhcp requests unaffected. For instance, in my env I have dhcp_agents_per_network=2, so If I create a network, and list the agents serving the network I will see the following: neutron dhcp-agent-list-hosting-net test +--+++---+ | id | host | admin_state_up | alive | +--+++---+ | 6dd09649-5e24-403b-9654-7aa0f69f04fb | host1 | True | :-) | | 7d47721a-2725-45f8-b7c4-2731cfabdb48 | host2 | True | :-) | +--+++---+ Isn't that what you're after? Cheers, Armando On 21 October 2014 22:26, Noel Burton-Krahn n...@pistoncloud.com wrote: We currently have a mechanism for restarting the DHCP agent on another node, but we'd like the new agent to take over all the old networks of the failed dhcp instance. Right now, since dhcp agents are distinguished by host, and the host has to match the host of the ovs agent, and the ovs agent's host has to be unique per node, the new dhcp agent is registered as a completely new agent and doesn't take over the failed agent's networks. I'm looking for a way to give the new agent the same roles as the previous one. -- Noel On Tue, Oct 21, 2014 at 12:12 AM, Kevin Benton blak...@gmail.com wrote: No, unfortunately when the DHCP agent dies there isn't automatic rescheduling at the moment. On Mon, Oct 20, 2014 at 11:56 PM, Noel Burton-Krahn n...@pistoncloud.com wrote: Thanks for the pointer! I like how the first google hit for this is: Add details on dhcp_agents_per_network option for DHCP agent HA https://bugs.launchpad.net/openstack-manuals/+bug/1370934 :) Seems reasonable to set dhcp_agents_per_network 1. What happens when a DHCP agent dies? Does the scheduler automatically bind another agent to that network? Cheers, -- Noel On Mon, Oct 20, 2014 at 9:03 PM, Jian Wen wenjia...@gmail.com wrote: See dhcp_agents_per_network in neutron.conf. https://bugs.launchpad.net/neutron/+bug/1174132 2014-10-21 6:47 GMT+08:00 Noel Burton-Krahn n...@pistoncloud.com: I've been working on failover for dhcp and L3 agents. I see that in [1], multiple dhcp agents can host the same network. However, it looks like I have to manually assign networks to multiple dhcp agents, which won't work. Shouldn't multiple dhcp agents automatically fail over? [1] http://docs.openstack.org/trunk/config-reference/content/multi_agent_demo_configuration.html ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Best, Jian ___ 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 -- Kevin Benton ___ 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
Re: [openstack-dev] [neutron] HA of dhcp agents?
Thanks for the pointer! I like how the first google hit for this is: Add details on dhcp_agents_per_network option for DHCP agent HA https://bugs.launchpad.net/openstack-manuals/+bug/1370934 :) Seems reasonable to set dhcp_agents_per_network 1. What happens when a DHCP agent dies? Does the scheduler automatically bind another agent to that network? Cheers, -- Noel On Mon, Oct 20, 2014 at 9:03 PM, Jian Wen wenjia...@gmail.com wrote: See dhcp_agents_per_network in neutron.conf. https://bugs.launchpad.net/neutron/+bug/1174132 2014-10-21 6:47 GMT+08:00 Noel Burton-Krahn n...@pistoncloud.com: I've been working on failover for dhcp and L3 agents. I see that in [1], multiple dhcp agents can host the same network. However, it looks like I have to manually assign networks to multiple dhcp agents, which won't work. Shouldn't multiple dhcp agents automatically fail over? [1] http://docs.openstack.org/trunk/config-reference/content/multi_agent_demo_configuration.html ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Best, Jian ___ 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
Re: [openstack-dev] [neutron] HA of dhcp agents?
No, unfortunately when the DHCP agent dies there isn't automatic rescheduling at the moment. On Mon, Oct 20, 2014 at 11:56 PM, Noel Burton-Krahn n...@pistoncloud.com wrote: Thanks for the pointer! I like how the first google hit for this is: Add details on dhcp_agents_per_network option for DHCP agent HA https://bugs.launchpad.net/openstack-manuals/+bug/1370934 :) Seems reasonable to set dhcp_agents_per_network 1. What happens when a DHCP agent dies? Does the scheduler automatically bind another agent to that network? Cheers, -- Noel On Mon, Oct 20, 2014 at 9:03 PM, Jian Wen wenjia...@gmail.com wrote: See dhcp_agents_per_network in neutron.conf. https://bugs.launchpad.net/neutron/+bug/1174132 2014-10-21 6:47 GMT+08:00 Noel Burton-Krahn n...@pistoncloud.com: I've been working on failover for dhcp and L3 agents. I see that in [1], multiple dhcp agents can host the same network. However, it looks like I have to manually assign networks to multiple dhcp agents, which won't work. Shouldn't multiple dhcp agents automatically fail over? [1] http://docs.openstack.org/trunk/config-reference/content/multi_agent_demo_configuration.html ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Best, Jian ___ 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 -- Kevin Benton ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
Re: [openstack-dev] [neutron] HA of dhcp agents?
We currently have a mechanism for restarting the DHCP agent on another node, but we'd like the new agent to take over all the old networks of the failed dhcp instance. Right now, since dhcp agents are distinguished by host, and the host has to match the host of the ovs agent, and the ovs agent's host has to be unique per node, the new dhcp agent is registered as a completely new agent and doesn't take over the failed agent's networks. I'm looking for a way to give the new agent the same roles as the previous one. -- Noel On Tue, Oct 21, 2014 at 12:12 AM, Kevin Benton blak...@gmail.com wrote: No, unfortunately when the DHCP agent dies there isn't automatic rescheduling at the moment. On Mon, Oct 20, 2014 at 11:56 PM, Noel Burton-Krahn n...@pistoncloud.com wrote: Thanks for the pointer! I like how the first google hit for this is: Add details on dhcp_agents_per_network option for DHCP agent HA https://bugs.launchpad.net/openstack-manuals/+bug/1370934 :) Seems reasonable to set dhcp_agents_per_network 1. What happens when a DHCP agent dies? Does the scheduler automatically bind another agent to that network? Cheers, -- Noel On Mon, Oct 20, 2014 at 9:03 PM, Jian Wen wenjia...@gmail.com wrote: See dhcp_agents_per_network in neutron.conf. https://bugs.launchpad.net/neutron/+bug/1174132 2014-10-21 6:47 GMT+08:00 Noel Burton-Krahn n...@pistoncloud.com: I've been working on failover for dhcp and L3 agents. I see that in [1], multiple dhcp agents can host the same network. However, it looks like I have to manually assign networks to multiple dhcp agents, which won't work. Shouldn't multiple dhcp agents automatically fail over? [1] http://docs.openstack.org/trunk/config-reference/content/multi_agent_demo_configuration.html ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Best, Jian ___ 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 -- Kevin Benton ___ 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
Re: [openstack-dev] [neutron] HA of dhcp agents?
As far as I can tell when you specify: dhcp_agents_per_network = X 1 The server binds the network to all the agents (up to X), which means that you have multiple instances of dnsmasq serving dhcp requests at the same time. If one agent dies, there is no fail-over needed per se, as the other agent will continue to server dhcp requests unaffected. For instance, in my env I have dhcp_agents_per_network=2, so If I create a network, and list the agents serving the network I will see the following: neutron dhcp-agent-list-hosting-net test +--+++---+ | id | host | admin_state_up | alive | +--+++---+ | 6dd09649-5e24-403b-9654-7aa0f69f04fb | host1 | True | :-) | | 7d47721a-2725-45f8-b7c4-2731cfabdb48 | host2 | True | :-) | +--+++---+ Isn't that what you're after? Cheers, Armando On 21 October 2014 22:26, Noel Burton-Krahn n...@pistoncloud.com wrote: We currently have a mechanism for restarting the DHCP agent on another node, but we'd like the new agent to take over all the old networks of the failed dhcp instance. Right now, since dhcp agents are distinguished by host, and the host has to match the host of the ovs agent, and the ovs agent's host has to be unique per node, the new dhcp agent is registered as a completely new agent and doesn't take over the failed agent's networks. I'm looking for a way to give the new agent the same roles as the previous one. -- Noel On Tue, Oct 21, 2014 at 12:12 AM, Kevin Benton blak...@gmail.com wrote: No, unfortunately when the DHCP agent dies there isn't automatic rescheduling at the moment. On Mon, Oct 20, 2014 at 11:56 PM, Noel Burton-Krahn n...@pistoncloud.com wrote: Thanks for the pointer! I like how the first google hit for this is: Add details on dhcp_agents_per_network option for DHCP agent HA https://bugs.launchpad.net/openstack-manuals/+bug/1370934 :) Seems reasonable to set dhcp_agents_per_network 1. What happens when a DHCP agent dies? Does the scheduler automatically bind another agent to that network? Cheers, -- Noel On Mon, Oct 20, 2014 at 9:03 PM, Jian Wen wenjia...@gmail.com wrote: See dhcp_agents_per_network in neutron.conf. https://bugs.launchpad.net/neutron/+bug/1174132 2014-10-21 6:47 GMT+08:00 Noel Burton-Krahn n...@pistoncloud.com: I've been working on failover for dhcp and L3 agents. I see that in [1], multiple dhcp agents can host the same network. However, it looks like I have to manually assign networks to multiple dhcp agents, which won't work. Shouldn't multiple dhcp agents automatically fail over? [1] http://docs.openstack.org/trunk/config-reference/content/multi_agent_demo_configuration.html ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Best, Jian ___ 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 -- Kevin Benton ___ 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
Re: [openstack-dev] [neutron] HA of dhcp agents?
Hi Armando, Sort of... but what happens when the second one dies? If one DHCP agent dies, I need to be able to start a new DHCP agent on another host and take over from it. As far as I can tell right now, when one DHCP agent dies, another doesn't take up the slack. I have the same problem wit L3 agents by the way, that's next on my list -- Noel On Tue, Oct 21, 2014 at 12:52 PM, Armando M. arma...@gmail.com wrote: As far as I can tell when you specify: dhcp_agents_per_network = X 1 The server binds the network to all the agents (up to X), which means that you have multiple instances of dnsmasq serving dhcp requests at the same time. If one agent dies, there is no fail-over needed per se, as the other agent will continue to server dhcp requests unaffected. For instance, in my env I have dhcp_agents_per_network=2, so If I create a network, and list the agents serving the network I will see the following: neutron dhcp-agent-list-hosting-net test +--+++---+ | id | host | admin_state_up | alive | +--+++---+ | 6dd09649-5e24-403b-9654-7aa0f69f04fb | host1 | True | :-) | | 7d47721a-2725-45f8-b7c4-2731cfabdb48 | host2 | True | :-) | +--+++---+ Isn't that what you're after? Cheers, Armando On 21 October 2014 22:26, Noel Burton-Krahn n...@pistoncloud.com wrote: We currently have a mechanism for restarting the DHCP agent on another node, but we'd like the new agent to take over all the old networks of the failed dhcp instance. Right now, since dhcp agents are distinguished by host, and the host has to match the host of the ovs agent, and the ovs agent's host has to be unique per node, the new dhcp agent is registered as a completely new agent and doesn't take over the failed agent's networks. I'm looking for a way to give the new agent the same roles as the previous one. -- Noel On Tue, Oct 21, 2014 at 12:12 AM, Kevin Benton blak...@gmail.com wrote: No, unfortunately when the DHCP agent dies there isn't automatic rescheduling at the moment. On Mon, Oct 20, 2014 at 11:56 PM, Noel Burton-Krahn n...@pistoncloud.com wrote: Thanks for the pointer! I like how the first google hit for this is: Add details on dhcp_agents_per_network option for DHCP agent HA https://bugs.launchpad.net/openstack-manuals/+bug/1370934 :) Seems reasonable to set dhcp_agents_per_network 1. What happens when a DHCP agent dies? Does the scheduler automatically bind another agent to that network? Cheers, -- Noel On Mon, Oct 20, 2014 at 9:03 PM, Jian Wen wenjia...@gmail.com wrote: See dhcp_agents_per_network in neutron.conf. https://bugs.launchpad.net/neutron/+bug/1174132 2014-10-21 6:47 GMT+08:00 Noel Burton-Krahn n...@pistoncloud.com: I've been working on failover for dhcp and L3 agents. I see that in [1], multiple dhcp agents can host the same network. However, it looks like I have to manually assign networks to multiple dhcp agents, which won't work. Shouldn't multiple dhcp agents automatically fail over? [1] http://docs.openstack.org/trunk/config-reference/content/multi_agent_demo_configuration.html ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Best, Jian ___ 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 -- Kevin Benton ___ 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 ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
Re: [openstack-dev] [neutron] HA of dhcp agents?
See dhcp_agents_per_network in neutron.conf. https://bugs.launchpad.net/neutron/+bug/1174132 2014-10-21 6:47 GMT+08:00 Noel Burton-Krahn n...@pistoncloud.com: I've been working on failover for dhcp and L3 agents. I see that in [1], multiple dhcp agents can host the same network. However, it looks like I have to manually assign networks to multiple dhcp agents, which won't work. Shouldn't multiple dhcp agents automatically fail over? [1] http://docs.openstack.org/trunk/config-reference/content/multi_agent_demo_configuration.html ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev -- Best, Jian ___ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
