RPCVersionCapError: Requested message version, 4.17 is incompatible. It needs to be equal in major version and less than or equal in minor version as the specified version cap 4.11.

【问题描述】

RPCVersionCapError: Requested message version, 4.17 is incompatible. It needs to be equal in major version and less than or equal in minor version as the specified version cap 4.11.

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions File "/usr/lib/python2.7/site-packages/nova/api/openstack/extensions.py", line 336, in wrapped

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions return f(*args, **kwargs)

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions File "/usr/lib/python2.7/site-packages/nova/api/openstack/compute/servers.py", line 865, in delete

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions self._delete(req.environ['nova.context'], req, id)

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions File "/usr/lib/python2.7/site-packages/nova/api/openstack/compute/servers.py", line 719, in _delete

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions self.compute_api.delete(context, instance)

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions File "/usr/lib/python2.7/site-packages/nova/compute/api.py", line 200, in inner

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions return function(self, context, instance, *args, **kwargs)

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions File "/usr/lib/python2.7/site-packages/nova/compute/api.py", line 208, in _wrapped

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions return fn(self, context, instance, *args, **kwargs)

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions File "/usr/lib/python2.7/site-packages/nova/compute/api.py", line 148, in inner

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions return f(self, context, instance, *args, **kw)

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions File "/usr/lib/python2.7/site-packages/nova/compute/api.py", line 2130, in delete

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions self._delete_instance(context, instance)

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions File "/usr/lib/python2.7/site-packages/nova/compute/api.py", line 2121, in _delete_instance

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions task_state=task_states.DELETING)

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions File "/usr/lib/python2.7/site-packages/nova/compute/api.py", line 1788, in _delete

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions self.detach_usb_list(context, instance)

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions File "/usr/lib/python2.7/site-packages/nova/compute/api.py", line 200, in inner

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions return function(self, context, instance, *args, **kwargs)

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions File "/usr/lib/python2.7/site-packages/nova/compute/api.py", line 191, in wrapped

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions return function(self, context, instance, *args, **kwargs)

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions File "/usr/lib/python2.7/site-packages/nova/compute/api.py", line 208, in _wrapped

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions return fn(self, context, instance, *args, **kwargs)

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions File "/usr/lib/python2.7/site-packages/nova/compute/api.py", line 3596, in detach_usb_list

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions return self.compute_rpcapi.detach_usb_list(context, instance)

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions File "/usr/lib/python2.7/site-packages/nova/compute/rpcapi.py", line 458, in detach_usb_list

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions return cctxt.call(ctxt, 'detach_usb_list', instance=instance)

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/client.py", line 164, in call

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions self._check_version_cap(msg.get('version'))

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/client.py", line 121, in _check_version_cap

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions version_cap=self.version_cap)

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions RPCVersionCapError: Requested message version, 4.17 is incompatible. It needs to be equal in major version and less than or equal in minor version as the specified version cap 4.11.

2019-08-16 10:33:21.706 35 ERROR nova.api.openstack.extensions

2019-08-16 10:33:21.708 35 INFO nova.api.openstack.wsgi [req-2bd614de-973d-48fe-b9c2-392a65195a62 11668b80d3264ff7b0e602c4b603af5e 7fadd01436224d6c8d317c5a321fb3f6 - default default] HTTP exception thrown: Unexpected API Error. Please report this at http://bugs.launchpad.net/nova/ and attach the Nova API log if possible.

【问题定位】

日志显示版本不兼容，RPC当前版本为4.17，但是应该使用4.11或者之前的版本。

重启nova-api服务，此问题不再复现。

后来查看了nova的配置文件，研究对比了一下和其他环境的区别。

[upgrade_levels]

compute = auto

在 /etc/nova/nova.conf 配置文件里面，上面红色字体的参数为auto，这个参数主要是针对同时存在多个版本的nova-compute设计的。

nova-api的启动顺序在nova-compute之前，所以，在最开始的时候并不能取到nova-compute的版本，直接取了默认的mitaka，也就是4.11的版本。

然后在调用nova-api的时候，如果nova-compute的版本不是mitaka，版本就会有不匹配的问题。

但是在重启的时候， 通过上面的函数重新取了nova-compute的版本。

【解决方法】

将 /etc/nova/nova.conf 配置文件里面的红色字段修改为None：

[upgrade_levels]

compute = None

在上代码中，如果取到的imp_version为None，则直接返回True。