Bug 1399071

[stack@undercloud-0 ~]$ neutron router-create router01
Not enough l3 agents available to ensure HA. Minimum required 2, available 1.
Neutron server returns request_ids: ['req-c89cc076-b428-48a3-bd39-89e70a0f579f']

The error in neutron server log:
2016-11-28 13:55:34.142 326469 ERROR neutron.api.v2.resource HANotEnoughAvailableAgents: Not enough l3 agents available to ensure HA. Minimum required 2, available 1.

This is the config section in neutron.conf:

# DEPRECATED: Minimum number of L3 agents that have to be available in order to
# allow a new HA router to be scheduled. This option is deprecated in the
# Newton release and will be removed for the Ocata release where the scheduling
# of new HA routers will always be allowed. (integer value)
# This option is deprecated for removal.
# Its value may be silently ignored in the future.
#min_l3_agents_per_router = 2

In /etc/puppet/modules/neutron/manifests/server.pp:

  if $min_l3_agents_per_router {
    warning('min_l3_agents_per_router is deprecated, has no effect and will be removed for the Ocata release.')
  }

My take on this is that the correct thing to do would be to repair the network node that went down or deploy a new one first before trying to add a new router.

However, it is odd that you can't reconfigure min_l3_agents_per_router with puppet-neutron to be set to 1 (or disable it somehow...-1?), given that logic would match the Ocata behavior which will be the new default behavior.

Regardless, I think this is a bug for DFG:Networking as it is for Neutron deployment and configuration.

Since puppet doesn't support it directly, does arbitrary extra config work:


ControllerExtraConfig:
    neutron::config::server_config:
         default/min_l3_agents_per_router:
             value: '1'

If the configuration is going to be removed from neutron in Ocata, we would only reasonably add support for configuring in puppet-neutron on the newton branch and we'd introduce it as a configuration item that was deprecated from the start. Given the availability of a workaround, the nature of the issue and that it only affects <= newton, I feel this would not get much interest upstream.

(In reply to Brent Eagles from comment #3)
> Since puppet doesn't support it directly, does arbitrary extra config work:
> 
> 
> ControllerExtraConfig:
>     neutron::config::server_config:
>          default/min_l3_agents_per_router:
>              value: '1'
> 

Thanks, Brent! It worked for me with a slight modification:

  ControllerExtraConfig:
    neutron::config::server_config:
      DEFAULT/min_l3_agents_per_router:
        value: '1'

I'm dropping the blocker flag. Since this option is getting removed in Ocata I think we just need to document the workaround in case users will end up in this situation.

For the record this has been the behavior in OSP 7, 8 and 9 (Having a min of 2, which impacts transient issues as detailed in comment 0). Since you can set it to 1 with the snippet Marius provided in comment 4 I can't see how this would be a blocker.

Verified with openstack-puppet-modules-10.0.0-0.20170307021643.0333c73.el7ost.noarch

Created a router when both networkers were up, then shutdown one of them and created a second router

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHEA-2017:1245