docker - redis-ha : Unable to create specified number of masters in cluster

Question

我正在尝试使用以下命令创建一个由 3 个主节点、3 个从节点和 3 个哨兵组成的集群。

helm install --set replicas.master=3 --set replicas.slave=3 stable/redis-ha

但我看到只有 1 个 master 被创建。 Helm ——版本 0.2.3 GIT repo :https://github.com/kubernetes/charts/tree/master/stable/redis-ha

以下是 helm 的日志。

=>     NAME                         DESIRED  CURRENT  AGE
=>    eloping-fox-redis-ha-master  3        1        9s

我是不是遗漏了什么或者有什么问题？ 我已经尝试了这多个项目，每次只创建 1 个母版。

我正在使用 VM/Minikube/Docker 在 Windows 机器上尝试这个。

PS C:\Users\rootus> helm install --set replicas.master=3 --set replicas.slave=3  stable/redis-ha
NAME:   eloping-fox
LAST DEPLOYED: Wed Nov  1 16:34:58 2017
NAMESPACE: default
STATUS: DEPLOYED

RESOURCES:
==> v1beta1/Deployment
NAME                           DESIRED  CURRENT  UP-TO-DATE  AVAILABLE  AGE
eloping-fox-redis-ha           3        3        3           0          9s
eloping-fox-redis-ha-sentinel  3        3        3           0          9s

==> v1beta1/StatefulSet
NAME                         DESIRED  CURRENT  AGE
eloping-fox-redis-ha-master  3        1        9s

==> v1/Pod(related)
NAME                                            READY  STATUS             RESTARTS  AGE
eloping-fox-redis-ha-167683871-2rhn8            0/1    ContainerCreating  0         9s
eloping-fox-redis-ha-167683871-cmjjk            0/1    ContainerCreating  0         9s
eloping-fox-redis-ha-167683871-jf4sn            0/1    ContainerCreating  0         9s
eloping-fox-redis-ha-sentinel-2596454939-9qq06  0/1    ContainerCreating  0         9s
eloping-fox-redis-ha-sentinel-2596454939-ngwcf  0/1    ContainerCreating  0         9s
eloping-fox-redis-ha-sentinel-2596454939-pwkbx  0/1    ContainerCreating  0         9s

==> v1/Service
NAME                  TYPE       CLUSTER-IP  EXTERNAL-IP  PORT(S)    AGE
redis-sentinel        ClusterIP  10.0.0.122  <none>       26379/TCP  9s
eloping-fox-redis-ha  ClusterIP  10.0.0.149  <none>       6379/TCP   9s


NOTES:
Redis cluster can be accessed via port 6379 on the following DNS name from within your cluster:
eloping-fox-redis-ha.default.svc.cluster.local

To connect to your Redis server:

1. Run a Redis pod that you can use as a client:

   kubectl exec -it eloping-fox-redis-ha-master-0 bash

2. Connect using the Redis CLI:

  redis-cli -h eloping-fox-redis-ha.default.svc.cluster.local

============================================= ==

Answer 1

使用 stable/redis-ha 一切正常 Helm 图。

这似乎是您的 minikube 的问题环境。

默认 minikube使用 2 CPU 启动 VM和 2048M RAM .

来自 stable/redis-ha 的默认 CPU 和内存资源 Helm 图如下:

resources:
  master:
    requests:
      memory: 200Mi
      cpu: 100m
    limits:
      memory: 700Mi
  slave:
    requests:
      memory: 200Mi
      cpu: 100m
    limits:
      memory: 200Mi
  sentinel:
    requests:
      memory: 200Mi
      cpu: 100m
    limits:
      memory: 200Mi

部署时 stable/redis-ha Helm chart 与 3 masters和 3 slaves它只创建 1 master ，因为你的 VM 上缺少带有 minikube 的资源:

$ kubectl get pod
NAME                                                   READY     STATUS    RESTARTS   AGE
melting-armadillo-redis-ha-2438719374-8ghdn            1/1       Running   0          2m
melting-armadillo-redis-ha-2438719374-rlq24            1/1       Running   0          2m
melting-armadillo-redis-ha-2438719374-zlg4p            1/1       Running   0          2m
melting-armadillo-redis-ha-master-0                    2/2       Running   0          2m
melting-armadillo-redis-ha-master-1                    0/2       Pending   0          4s
melting-armadillo-redis-ha-sentinel-1377673986-004m8   1/1       Running   0          2m
melting-armadillo-redis-ha-sentinel-1377673986-gcpj2   1/1       Running   0          2m
melting-armadillo-redis-ha-sentinel-1377673986-jh73w   1/1       Running   0          2m

第二个redis master的Pod有Pending状态因为:

  FirstSeen LastSeen    Count   From            SubObjectPath   Type        Reason          Message
  --------- --------    -----   ----            -------------   --------    ------          -------
  16s       1s      6   default-scheduler           Warning     FailedScheduling    No nodes are available that match all of the following predicates:: Insufficient memory (1).

所以您有两种方法可以解决您的问题:

1. 创建您的 minikube环境至少 4096M RAM .
2. 部署 stable/redis-ha Helm chart 与 3 masters和 3 slaves内存资源减少。

第一种方式是:

开始minikube与 4096M RAM :

$ minikube start --memory 4096
Starting local Kubernetes v1.7.5 cluster...
Starting VM...
Getting VM IP address...
Moving files into cluster...
Setting up certs...
Connecting to cluster...
Setting up kubeconfig...
Starting cluster components...
Kubectl is now configured to use the cluster.

部署 stable/redis-ha Helm chart 与 3 masters和 3 slaves :

$ helm install --set replicas.master=3 --set replicas.slave=3 stable/redis-ha 

最后我们得到:

$ kubectl get pod
NAME                                                 READY     STATUS    RESTARTS   AGE
maudlin-ladybug-redis-ha-1801622981-brmqp            1/1       Running   0          3m
maudlin-ladybug-redis-ha-1801622981-klhr1            1/1       Running   0          3m
maudlin-ladybug-redis-ha-1801622981-mpf3j            1/1       Running   0          3m
maudlin-ladybug-redis-ha-master-0                    2/2       Running   0          3m
maudlin-ladybug-redis-ha-master-1                    2/2       Running   0          1m
maudlin-ladybug-redis-ha-master-2                    2/2       Running   0          1m
maudlin-ladybug-redis-ha-sentinel-3633913943-f8x2c   1/1       Running   0          3m
maudlin-ladybug-redis-ha-sentinel-3633913943-ltvk4   1/1       Running   0          3m
maudlin-ladybug-redis-ha-sentinel-3633913943-xwclg   1/1       Running   0          3m

第二种方式是:

部署 stable/redis-ha Helm chart 与 3 masters和 3 slaves并减少内存资源:

helm install --set replicas.master=3 --set replicas.slave=3 --set resources.master.requests.memory=100Mi --set resources.slave.requests.memory=100Mi --set resources.sentinel.requests.memory=100Mi stable/redis-ha

最后我们得到:

$ kubectl get pod
NAME                                                       READY     STATUS    RESTARTS   AGE
exacerbated-jellyfish-redis-ha-3444643229-085f4            1/1       Running   0          43s
exacerbated-jellyfish-redis-ha-3444643229-bl221            1/1       Running   0          43s
exacerbated-jellyfish-redis-ha-3444643229-qx62b            1/1       Running   0          43s
exacerbated-jellyfish-redis-ha-master-0                    2/2       Running   0          43s
exacerbated-jellyfish-redis-ha-master-1                    2/2       Running   0          36s
exacerbated-jellyfish-redis-ha-master-2                    2/2       Running   0          29s
exacerbated-jellyfish-redis-ha-sentinel-1441222589-czsvx   1/1       Running   0          43s
exacerbated-jellyfish-redis-ha-sentinel-1441222589-ql6n6   1/1       Running   0          43s
exacerbated-jellyfish-redis-ha-sentinel-1441222589-qql1f   1/1       Running   0          43s