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根据指令here，我们有一个使用CoreOS在AWS上运行的小型测试Kubernetes集群。目前，这仅包含主节点和工作节点。在过去的几周里，我们一直在运行这个集群，我们注意到工作者实例偶尔会失败。第一次发生这种情况后，实例随后被自动扩展组杀死并重新启动。今天发生了同样的事情，但我们能够在关闭实例之前登录实例并检索一些信息，但它仍然存在究竟是什么导致了这个问题，我不清楚。Kubernetes节点失败（CoreOS/AWS/Kubernetes堆栈）
节点故障似乎发生在不规则的基础上，并且没有证据表明有任何异常情况会导致这种情况发生（外部负载等）。
偶然发生故障（kubernetes节点状态为“未就绪”），实例仍在运行，但kubelet和docker服务（start failed with result 'dependency'）处于非活动状态。 flanneld服务正在运行，但是在看到节点故障后的重启时间。
节点故障发生时的日志似乎没有显示任何明显的指向故障原因的东西。有大约在时间一对夫妇kubelet，包装错误的失败被认为：
`Jul 22 07:25:33 ip-10-0-0-92.ec2.internal kubelet-wrapper[1204]: E0722 07:25:33.121506 1204 kubelet.go:2745] Error updating node status, will retry: nodes "ip-10-0-0-92.ec2.internal" cannot be updated: the object has been modified; please apply your changes to the latest version and try again`
`Jul 22 07:25:34 ip-10-0-0-92.ec2.internal kubelet-wrapper[1204]: E0722 07:25:34.557047 1204 event.go:193] Server rejected event '&api.Event{TypeMeta:unversioned.TypeMeta{Kind:"", APIVersion:""}, ObjectMeta:api.ObjectMeta{Name:"ip-10-0-0-92.ec2.internal.1462693ef85b56d8", GenerateName:"", Namespace:"default", SelfLink:"", UID:"", ResourceVersion:"4687622", Generation:0, CreationTimestamp:unversioned.Time{Time:time.Time{sec:0, nsec:0, loc:(*time.Location)(nil)}}, DeletionTimestamp:(*unversioned.Time)(nil), DeletionGracePeriodSeconds:(*int64)(nil), Labels:map[string]string(nil), Annotations:map[string]string(nil)}, InvolvedObject:api.ObjectReference{Kind:"Node", Namespace:"", Name:"ip-10-0-0-92.ec2.internal", UID:"ip-10-0-0-92.ec2.internal", APIVersion:"", ResourceVersion:"", FieldPath:""}, Reason:"NodeHasSufficientDisk", Message:"Node ip-10-0-0-92.ec2.internal status is now: NodeHasSufficientDisk", Source:api.EventSource{Component:"kubelet", Host:"ip-10-0-0-92.ec2.internal"}, FirstTimestamp:unversioned.Time{Time:time.Time{sec:63604448947, nsec:0, loc:(*time.Location)(0x3b1a5c0)}}, LastTimestamp:unversioned.Time{Time:time.Time{sec:63604769134, nsec:388015022, loc:(*time.Location)(0x3b1a5c0)}}, Count:2, Type:"Normal"}': 'events "ip-10-0-0-92.ec2.internal.1462693ef85b56d8" not found' (will not retry!)
Jul 22 07:25:34 ip-10-0-0-92.ec2.internal kubelet-wrapper[1204]: E0722 07:25:34.560636 1204 event.go:193] Server rejected event '&api.Event{TypeMeta:unversioned.TypeMeta{Kind:"", APIVersion:""}, ObjectMeta:api.ObjectMeta{Name:"ip-10-0-0-92.ec2.internal.14626941554cc358", GenerateName:"", Namespace:"default", SelfLink:"", UID:"", ResourceVersion:"4687645", Generation:0, CreationTimestamp:unversioned.Time{Time:time.Time{sec:0, nsec:0, loc:(*time.Location)(nil)}}, DeletionTimestamp:(*unversioned.Time)(nil), DeletionGracePeriodSeconds:(*int64)(nil), Labels:map[string]string(nil), Annotations:map[string]string(nil)}, InvolvedObject:api.ObjectReference{Kind:"Node", Namespace:"", Name:"ip-10-0-0-92.ec2.internal", UID:"ip-10-0-0-92.ec2.internal", APIVersion:"", ResourceVersion:"", FieldPath:""}, Reason:"NodeReady", Message:"Node ip-10-0-0-92.ec2.internal status is now: NodeReady", Source:api.EventSource{Component:"kubelet", Host:"ip-10-0-0-92.ec2.internal"}, FirstTimestamp:unversioned.Time{Time:time.Time{sec:63604448957, nsec:0, loc:(*time.Location)(0x3b1a5c0)}}, LastTimestamp:unversioned.Time{Time:time.Time{sec:63604769134, nsec:388022975, loc:(*time.Location)(0x3b1a5c0)}}, Count:2, Type:"Normal"}': 'events "ip-10-0-0-92.ec2.internal.14626941554cc358" not found' (will not retry!)`
其次是什么样子有些ETCD错误：
`Jul 22 07:27:04 ip-10-0-0-92.ec2.internal rkt[1214]: 2016-07-22 07:27:04,721 [WARNING][1305/140149086452400] calico.etcddriver.driver 810: etcd watch returned bad HTTP status topoll on index 5237916: 400
Jul 22 07:27:04 ip-10-0-0-92.ec2.internal rkt[1214]: 2016-07-22 07:27:04,721 [ERROR][1305/140149086452400] calico.etcddriver.driver 852: Error from etcd for index 5237916: {u'errorCode': 401, u'index': 5239005, u'message': u'The event in requested index is outdated and cleared', u'cause': u'the requested history has been cleared [5238006/5237916]'}; triggering a resync.
Jul 22 07:27:04 ip-10-0-0-92.ec2.internal rkt[1214]: 2016-07-22 07:27:04,721 [INFO][1305/140149086452400] calico.etcddriver.driver 916: STAT: Final watcher etcd response time: 0 in 630.6s (0.000/s) min=0.000ms mean=0.000ms max=0.000ms
Jul 22 07:27:04 ip-10-0-0-92.ec2.internal rkt[1214]: 2016-07-22 07:27:04,721 [INFO][1305/140149086452400] calico.etcddriver.driver 916: STAT: Final watcher processing time: 7 in 630.6s (0.011/s) min=90066.312ms mean=90078.569ms max=90092.505ms
Jul 22 07:27:04 ip-10-0-0-92.ec2.internal rkt[1214]: 2016-07-22 07:27:04,721 [INFO][1305/140149086452400] calico.etcddriver.driver 919: Watcher thread finished. Signalled to resync thread. Was at index 5237916. Queue length is 1.
Jul 22 07:27:04 ip-10-0-0-92.ec2.internal rkt[1214]: 2016-07-22 07:27:04,743 [WARNING][1305/140149192694448] calico.etcddriver.driver 291: Watcher died; resyncing.`
and a few minutes later a large number of failed connections to the master (10.0.0.50):
`Jul 22 07:36:41 ip-10-0-0-92.ec2.internal rkt[1214]: 2016-07-22 07:36:37,641 [WARNING][1305/140149086452400] urllib3.connectionpool 647: Retrying (Retry(total=2, connect=None, read=None, redirect=None)) after connection broken by 'NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7f7700b85b90>: Failed to establish a new connection: [Errno 113] Host is unreachable',)': http://10.0.0.50:2379/v2/keys/calico/v1?waitIndex=5239006&recursive=true&wait=true
Jul 22 07:36:41 ip-10-0-0-92.ec2.internal rkt[1214]: 2016-07-22 07:36:37,641 [INFO][1305/140149086452400] urllib3.connectionpool 213: Starting new HTTP connection (2): 10.0.0.50`
虽然这些错误都可能涉及到节点/实例失败，这些对我来说并不意味着很重要，当然似乎也没有提出潜在的原因 - 但是如果任何人在这里可以看到任何可能导致节点/实例失败的原因（以及我们如何能够去纠正这一点），将不胜感激！
您使用了多大的实例？我已经看到，当我使用太小的实例时，如果集群非常小（即1名工人），集群不能保持稳定。 –