为什么k8s里的redis总是重启?

dly7yett  于 2021-06-08  发布在  Redis
关注(0)|答案(3)|浏览(905)

redis pod疯狂重启。我怎样才能找出这种行为的原因?
我想,资源配额应该升级,但我不知道什么是最好的cpu/ram比率。为什么没有崩溃事件或日志?
以下是豆荚:

> kubectl get pods
    redis-master-5d9cfb54f8-8pbgq                     1/1     Running     33         3d16h

以下是日志:

> kubectl logs --follow redis-master-5d9cfb54f8-8pbgq
[1] 08 Sep 07:02:12.152 # Server started, Redis version 2.8.19
[1] 08 Sep 07:02:12.153 # WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis. To fix this issue run the command 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' as root, and add it to your /etc/rc.local in order to retain the setting after a reboot. Redis must be restarted after THP is disabled.
[1] 08 Sep 07:02:12.153 * The server is now ready to accept connections on port 6379
[1] 08 Sep 07:03:13.085 * 10000 changes in 60 seconds. Saving...
[1] 08 Sep 07:03:13.085 * Background saving started by pid 8
[8] 08 Sep 07:03:13.101 * DB saved on disk
[8] 08 Sep 07:03:13.101 * RDB: 0 MB of memory used by copy-on-write
[1] 08 Sep 07:03:13.185 * Background saving terminated with success
[1] 08 Sep 07:04:14.018 * 10000 changes in 60 seconds. Saving...
[1] 08 Sep 07:04:14.018 * Background saving started by pid 9
...
[93] 08 Sep 08:38:30.160 * DB saved on disk
[93] 08 Sep 08:38:30.164 * RDB: 2 MB of memory used by copy-on-write
[1] 08 Sep 08:38:30.259 * Background saving terminated with success
[1] 08 Sep 08:39:31.072 * 10000 changes in 60 seconds. Saving...
[1] 08 Sep 08:39:31.074 * Background saving started by pid 94

这是同一个吊舱以前的日志。

> kubectl logs --previous --follow redis-master-5d9cfb54f8-8pbgq
[1] 08 Sep 09:41:46.057 * Background saving terminated with success
[1] 08 Sep 09:42:47.073 * 10000 changes in 60 seconds. Saving...
[1] 08 Sep 09:42:47.076 * Background saving started by pid 140
[140] 08 Sep 09:43:14.398 * DB saved on disk
[140] 08 Sep 09:43:14.457 * RDB: 1 MB of memory used by copy-on-write
[1] 08 Sep 09:43:14.556 * Background saving terminated with success
[1] 08 Sep 09:44:15.073 * 10000 changes in 60 seconds. Saving...
[1] 08 Sep 09:44:15.077 * Background saving started by pid 141
[1 | signal handler] (1599558267) Received SIGTERM scheduling shutdown...
[1] 08 Sep 09:44:28.052 # User requested shutdown...
[1] 08 Sep 09:44:28.052 # There is a child saving an .rdb. Killing it!
[1] 08 Sep 09:44:28.052 * Saving the final RDB snapshot before exiting.
[1] 08 Sep 09:44:49.592 * DB saved on disk
[1] 08 Sep 09:44:49.592 # Redis is now ready to exit, bye bye...

这是吊舱的描述。正如你所看到的,限制是100mi,但我看不到阈值,在此阈值之后pod将重新启动。

> kubectl describe pod redis-master-5d9cfb54f8-8pbgq
Name:           redis-master-5d9cfb54f8-8pbgq
Namespace:      cryptoman
Priority:       0
Node:           gke-my-cluster-default-pool-818613a8-smmc/10.172.0.28
Start Time:     Fri, 04 Sep 2020 18:52:17 +0300
Labels:         app=redis
                pod-template-hash=5d9cfb54f8
                role=master
                tier=backend
Annotations:    <none>
Status:         Running
IP:             10.36.2.124
IPs:            <none>
Controlled By:  ReplicaSet/redis-master-5d9cfb54f8
Containers:
  master:
    Container ID:   docker://3479276666a41df502f1f9eb9bb2ff9cfa592f08a33e656e44179042b6233c6f
    Image:          k8s.gcr.io/redis:e2e
    Image ID:       docker-pullable://k8s.gcr.io/redis@sha256:f066bcf26497fbc55b9bf0769cb13a35c0afa2aa42e737cc46b7fb04b23a2f25
    Port:           6379/TCP
    Host Port:      0/TCP
    State:          Running
      Started:      Wed, 09 Sep 2020 10:27:56 +0300
    Last State:     Terminated
      Reason:       OOMKilled
      Exit Code:    0
      Started:      Wed, 09 Sep 2020 07:34:18 +0300
      Finished:     Wed, 09 Sep 2020 10:27:55 +0300
    Ready:          True
    Restart Count:  42
    Limits:
      cpu:     100m
      memory:  250Mi
    Requests:
      cpu:        100m
      memory:     250Mi
    Environment:  <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-5tds9 (ro)
Conditions:
  Type              Status
  Initialized       True
  Ready             True
  ContainersReady   True
  PodScheduled      True
Volumes:
  default-token-5tds9:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-5tds9
    Optional:    false
QoS Class:       Guaranteed
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                 node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
  Type    Reason          Age                   From                                                Message
  ----    ------          ----                  ----                                                -------
  Normal  SandboxChanged  52m (x42 over 4d13h)  kubelet, gke-my-cluster-default-pool-818613a8-smmc  Pod sandbox changed, it will be killed and re-created.
  Normal  Killing         52m (x42 over 4d13h)  kubelet, gke-my-cluster-default-pool-818613a8-smmc  Stopping container master
  Normal  Created         52m (x43 over 4d16h)  kubelet, gke-my-cluster-default-pool-818613a8-smmc  Created container master
  Normal  Started         52m (x43 over 4d16h)  kubelet, gke-my-cluster-default-pool-818613a8-smmc  Started container master
  Normal  Pulled          52m (x42 over 4d13h)  kubelet, gke-my-cluster-default-pool-818613a8-smmc  Container image "k8s.gcr.io/redis:e2e" already present on machine
soat7uwm

soat7uwm1#

这是它重新启动后的限制。cpu被限制了,内存被释放了。

Limits:
      cpu:     100m
      memory:  250Mi
``` `Reason: OOMKilled` 删除请求和限制
运行吊舱,确保它不会重新启动
如果你已经有普罗米修斯,运行vpa推荐程序来检查它需要多少资源。或者只需使用任何监控堆栈:gke prometheus、prometheus operator、datadog等来检查实际的资源消耗并相应地调整限制。
uttx8gqw

uttx8gqw2#

麦克斯的答案很完整。但是,如果您没有安装prometheus或者不想安装prometheus,那么在集群中安装metrics服务器项目有另一种简单的方法来检查实际的资源消耗。安装之后,您可以使用 kubectl top node 检查节点上的消耗,以及 kubectl top pod 检查豆荚的消耗量。我用它,非常有用。
或者您可以只增加cpu和内存限制,但无法确保容器需要多少资源。基本上会浪费资源。

olhwl3o2

olhwl3o23#

现在豆荚被驱逐了。我能找出原因吗?

NAME                                              READY   STATUS             RESTARTS   AGE
redis-master-7d97765bbb-7kjwn                     0/1     Evicted            0          38h
redis-master-7d97765bbb-kmc9g                     1/1     Running            0          30m
redis-master-7d97765bbb-sf2ss                     0/1     Evicted            0          30m

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