Kubernetes K8S之affinity亲和性与反亲和性详解与示例

 

Kubernetes K8S之Node节点亲和性与反亲和性以及Pod亲和性与反亲和性详解与示例

 

主机配置规划

服务器名称(hostname) 系统版本 配置 内网IP 外网IP(模拟)
k8s-master CentOS7.7 2C/4G/20G 172.16.1.110 10.0.0.110
k8s-node01 CentOS7.7 2C/4G/20G 172.16.1.111 10.0.0.111
k8s-node02 CentOS7.7 2C/4G/20G 172.16.1.112 10.0.0.112

 

亲和性和反亲和性

nodeSelector提供了一种非常简单的方法,将pods约束到具有特定标签的节点。而亲和性/反亲和性极大地扩展了可表达的约束类型。关键的增强是:

1、亲和性/反亲和性语言更具表达性。除了使用逻辑AND操作创建的精确匹配之外,该语言还提供了更多的匹配规则;

2、可以指示规则是优选项而不是硬要求,因此如果调度器不能满足,pod仍将被调度;

3、可以针对节点(或其他拓扑域)上运行的pods的标签进行约束,而不是针对节点的自身标签,这影响哪些Pod可以或不可以共处。

亲和特性包括两种类型:node节点亲和性/反亲和性 和 pod亲和性/反亲和性。pod亲和性/反亲和性约束针对的是pod标签而不是节点标签。

拓扑域是什么:多个node节点,拥有相同的label标签【节点标签的键值相同】,那么这些节点就处于同一个拓扑域。★★★★★

 

node节点亲和性

当前有两种类型的节点亲和性,称为requiredDuringSchedulingIgnoredDuringExecution preferredDuringSchedulingIgnoredDuringExecution,可以将它们分别视为“硬”【必须满足条件】和“软”【优选满足条件】要求。

前者表示Pod要调度到的节点必须满足规则条件,不满足则不会调度,pod会一直处于Pending状态;后者表示优先调度到满足规则条件的节点,如果不能满足再调度到其他节点。

名称中的 IgnoredDuringExecution 部分意味着,与nodeSelector的工作方式类似,如果节点上的标签在Pod运行时发生更改,使得pod上的亲和性规则不再满足,那么pod仍将继续在该节点上运行。

在未来,会计划提供requiredDuringSchedulingRequiredDuringExecution,类似requiredDuringSchedulingIgnoredDuringExecution。不同之处就是pod运行过程中如果节点不再满足pod的亲和性,则pod会在该节点中逐出。

节点亲和性语法支持以下运算符:In,NotIn,Exists,DoesNotExist,Gt,Lt。可以使用NotIn和DoesNotExist实现节点的反亲和行为

运算符关系:

  • In:label的值在某个列表中
  • NotIn:label的值不在某个列表中
  • Gt:label的值大于某个值
  • Lt:label的值小于某个值
  • Exists:某个label存在
  • DoesNotExist:某个label不存在
其他重要说明:

1、如果同时指定nodeSelector和nodeAffinity,则必须满足两个条件,才能将Pod调度到候选节点上。

2、如果在nodeAffinity类型下指定了多个nodeSelectorTerms对象【对象不能有多个,如果存在多个只有最后一个生效】,那么只有最后一个nodeSelectorTerms对象生效。

3、如果在nodeSelectorTerms下指定了多个matchExpressions列表,那么只要能满足其中一个matchExpressions,就可以将pod调度到某个节点上【针对节点硬亲和】。

4、如果在matchExpressions下有多个key列表,那么只有当所有key满足时,才能将pod调度到某个节点【针对硬亲和】。

5、在key下的values只要有一个满足条件,那么当前的key就满足条件

6、如果pod已经调度在该节点,当我们删除或修该节点的标签时,pod不会被移除。换句话说,亲和性选择只有在pod调度期间有效。

7、preferredDuringSchedulingIgnoredDuringExecution中的weight(权重)字段在1-100范围内。对于每个满足所有调度需求的节点(资源请求、RequiredDuringScheduling亲和表达式等),调度器将通过迭代该字段的元素来计算一个总和,如果节点与相应的匹配表达式匹配,则向该总和添加“权重”。然后将该分数与节点的其他优先级函数的分数结合起来。总得分最高的节点是最受欢迎的。

 

node节点亲和性示例

准备事项

给node节点打label标签

1 ###  --overwrite覆盖已存在的标签信息
2 kubectl label nodes k8s-node01 disk-type=ssd --overwrite
3 kubectl label nodes k8s-node01 cpu-num=12
4 
5 kubectl label nodes k8s-node02 disk-type=sata
6 kubectl label nodes k8s-node02 cpu-num=24

 

查询所有节点标签信息

1 [[email protected] ~]# kubectl get node -o wide --show-labels
2 NAME         STATUS   ROLES    AGE   VERSION   INTERNAL-IP    EXTERNAL-IP   OS-IMAGE                KERNEL-VERSION           CONTAINER-RUNTIME   LABELS
3 k8s-master   Ready    master   43d   v1.17.4   172.16.1.110   <none>        CentOS Linux 7 (Core)   3.10.0-1062.el7.x86_64   docker://19.3.8     beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-master,kubernetes.io/os=linux,node-role.kubernetes.io/master=
4 k8s-node01   Ready    <none>   43d   v1.17.4   172.16.1.111   <none>        CentOS Linux 7 (Core)   3.10.0-1062.el7.x86_64   docker://19.3.8     beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,cpu-num=12,disk-type=ssd,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node01,kubernetes.io/os=linux
5 k8s-node02   Ready    <none>   43d   v1.17.4   172.16.1.112   <none>        CentOS Linux 7 (Core)   3.10.0-1062.el7.x86_64   docker://19.3.8     beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,cpu-num=24,disk-type=sata,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node02,kubernetes.io/os=linux

参见上面,给k8s-node01打了cpu-num=12,disk-type=ssd标签;给k8s-node02打了cpu-num=24,disk-type=sata标签。

 

node硬亲和性示例

必须满足条件才能调度,否则不会调度

要运行的yaml文件

 1 [[email protected] nodeAffinity]# pwd
 2 /root/k8s_practice/scheduler/nodeAffinity
 3 [[email protected] nodeAffinity]# cat node_required_affinity.yaml
 4 apiVersion: apps/v1
 5 kind: Deployment
 6 metadata:
 7   name: node-affinity-deploy
 8   labels:
 9     app: nodeaffinity-deploy
10 spec:
11   replicas: 5
12   selector:
13     matchLabels:
14       app: myapp
15   template:
16     metadata:
17       labels:
18         app: myapp
19     spec:
20       containers:
21       - name: myapp-pod
22         image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
23         imagePullPolicy: IfNotPresent
24         ports:
25           - containerPort: 80
26       affinity:
27         nodeAffinity:
28           requiredDuringSchedulingIgnoredDuringExecution:
29             nodeSelectorTerms:
30             - matchExpressions:
31               # 表示node标签存在 disk-type=ssd 或 disk-type=sas
32               - key: disk-type
33                 operator: In
34                 values:
35                 - ssd
36                 - sas
37               # 表示node标签存在 cpu-num且值大于6
38               - key: cpu-num
39                 operator: Gt
40                 values:
41                 - "6"

 

运行yaml文件并查看状态

 1 [[email protected] nodeAffinity]# kubectl apply -f node_required_affinity.yaml 
 2 deployment.apps/node-affinity-deploy created
 3 [[email protected]master nodeAffinity]# 
 4 [[email protected] nodeAffinity]# kubectl get deploy -o wide
 5 NAME                   READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                      SELECTOR
 6 node-affinity-deploy   5/5     5            5           6s    myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp
 7 [[email protected]master nodeAffinity]# 
 8 [[email protected] nodeAffinity]# kubectl get rs -o wide
 9 NAME                              DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                                                      SELECTOR
10 node-affinity-deploy-5c88ffb8ff   5         5         5       11s   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp,pod-template-hash=5c88ffb8ff
11 [[email protected]master nodeAffinity]# 
12 [[email protected] nodeAffinity]# kubectl get pod -o wide
13 NAME                                    READY   STATUS    RESTARTS   AGE   IP             NODE         NOMINATED NODE   READINESS GATES
14 node-affinity-deploy-5c88ffb8ff-2mbfl   1/1     Running   0          15s   10.244.4.237   k8s-node01   <none>           <none>
15 node-affinity-deploy-5c88ffb8ff-9hjhk   1/1     Running   0          15s   10.244.4.235   k8s-node01   <none>           <none>
16 node-affinity-deploy-5c88ffb8ff-9rg75   1/1     Running   0          15s   10.244.4.239   k8s-node01   <none>           <none>
17 node-affinity-deploy-5c88ffb8ff-pqtfh   1/1     Running   0          15s   10.244.4.236   k8s-node01   <none>           <none>
18 node-affinity-deploy-5c88ffb8ff-zqpl8   1/1     Running   0          15s   10.244.4.238   k8s-node01   <none>           <none>

由上可见,再根据之前打的标签,很容易推断出当前pod只能调度在k8s-node01节点。

即使我们删除原来的rs,重新生成rs后pod依旧会调度到k8s-node01节点。如下:

 1 [[email protected] nodeAffinity]# kubectl delete rs node-affinity-deploy-5c88ffb8ff
 2 replicaset.apps "node-affinity-deploy-5c88ffb8ff" deleted
 3 [[email protected]master nodeAffinity]# 
 4 [[email protected] nodeAffinity]# kubectl get rs -o wide
 5 NAME                              DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                                                      SELECTOR
 6 node-affinity-deploy-5c88ffb8ff   5         5         2       4s    myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp,pod-template-hash=5c88ffb8ff
 7 [[email protected]master nodeAffinity]# 
 8 [[email protected] nodeAffinity]# kubectl get pod -o wide
 9 NAME                                    READY   STATUS    RESTARTS   AGE   IP             NODE         NOMINATED NODE   READINESS GATES
10 node-affinity-deploy-5c88ffb8ff-2v2tb   1/1     Running   0          11s   10.244.4.241   k8s-node01   <none>           <none>
11 node-affinity-deploy-5c88ffb8ff-gl4fm   1/1     Running   0          11s   10.244.4.240   k8s-node01   <none>           <none>
12 node-affinity-deploy-5c88ffb8ff-j26rg   1/1     Running   0          11s   10.244.4.244   k8s-node01   <none>           <none>
13 node-affinity-deploy-5c88ffb8ff-vhzmn   1/1     Running   0          11s   10.244.4.243   k8s-node01   <none>           <none>
14 node-affinity-deploy-5c88ffb8ff-xxj8m   1/1     Running   0          11s   10.244.4.242   k8s-node01   <none>           <none>

 

node软亲和性示例

优先调度到满足条件的节点,如果都不满足也会调度到其他节点。

要运行的yaml文件

 1 [[email protected] nodeAffinity]# pwd
 2 /root/k8s_practice/scheduler/nodeAffinity
 3 [[email protected] nodeAffinity]# cat node_preferred_affinity.yaml 
 4 apiVersion: apps/v1
 5 kind: Deployment
 6 metadata:
 7   name: node-affinity-deploy
 8   labels:
 9     app: nodeaffinity-deploy
10 spec:
11   replicas: 5
12   selector:
13     matchLabels:
14       app: myapp
15   template:
16     metadata:
17       labels:
18         app: myapp
19     spec:
20       containers:
21       - name: myapp-pod
22         image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
23         imagePullPolicy: IfNotPresent
24         ports:
25           - containerPort: 80
26       affinity:
27         nodeAffinity:
28           preferredDuringSchedulingIgnoredDuringExecution:
29           - weight: 1
30             preference:
31               matchExpressions:
32               # 表示node标签存在 disk-type=ssd 或 disk-type=sas
33               - key: disk-type
34                 operator: In
35                 values:
36                 - ssd
37                 - sas
38           - weight: 50
39             preference:
40               matchExpressions:
41               # 表示node标签存在 cpu-num且值大于16
42               - key: cpu-num
43                 operator: Gt
44                 values:
45                 - "16"

 

运行yaml文件并查看状态

 1 [[email protected] nodeAffinity]# kubectl apply -f node_preferred_affinity.yaml 
 2 deployment.apps/node-affinity-deploy created
 3 [[email protected]master nodeAffinity]# 
 4 [[email protected] nodeAffinity]# kubectl get deploy -o wide
 5 NAME                   READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                      SELECTOR
 6 node-affinity-deploy   5/5     5            5           9s    myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp
 7 [[email protected]master nodeAffinity]# 
 8 [[email protected] nodeAffinity]# kubectl get rs -o wide
 9 NAME                             DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                                                      SELECTOR
10 node-affinity-deploy-d5d9cbc8d   5         5         5       13s   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp,pod-template-hash=d5d9cbc8d
11 [[email protected]master nodeAffinity]# 
12 [[email protected] nodeAffinity]# kubectl get pod -o wide
13 NAME                                   READY   STATUS    RESTARTS   AGE   IP             NODE         NOMINATED NODE   READINESS GATES
14 node-affinity-deploy-d5d9cbc8d-bv86t   1/1     Running   0          18s   10.244.2.243   k8s-node02   <none>           <none>
15 node-affinity-deploy-d5d9cbc8d-dnbr8   1/1     Running   0          18s   10.244.2.244   k8s-node02   <none>           <none>
16 node-affinity-deploy-d5d9cbc8d-ldq82   1/1     Running   0          18s   10.244.2.246   k8s-node02   <none>           <none>
17 node-affinity-deploy-d5d9cbc8d-nt74q   1/1     Running   0          18s   10.244.4.2     k8s-node01   <none>           <none>
18 node-affinity-deploy-d5d9cbc8d-rt5nb   1/1     Running   0          18s   10.244.2.245   k8s-node02   <none>           <none>

由上可见,再根据之前打的标签,很容易推断出当前pod会【优先】调度在k8s-node02节点。

 

node软硬亲和性联合示例

硬亲和性与软亲和性一起使用

要运行的yaml文件

 1 [[email protected] nodeAffinity]# pwd
 2 /root/k8s_practice/scheduler/nodeAffinity
 3 [[email protected] nodeAffinity]# cat node_affinity.yaml 
 4 apiVersion: apps/v1
 5 kind: Deployment
 6 metadata:
 7   name: node-affinity-deploy
 8   labels:
 9     app: nodeaffinity-deploy
10 spec:
11   replicas: 5
12   selector:
13     matchLabels:
14       app: myapp
15   template:
16     metadata:
17       labels:
18         app: myapp
19     spec:
20       containers:
21       - name: myapp-pod
22         image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
23         imagePullPolicy: IfNotPresent
24         ports:
25           - containerPort: 80
26       affinity:
27         nodeAffinity:
28           requiredDuringSchedulingIgnoredDuringExecution:
29             nodeSelectorTerms:
30               # 表示node标签存在 cpu-num且值大于10
31             - matchExpressions:
32               - key: cpu-num
33                 operator: Gt
34                 values:
35                 - "10"
36           preferredDuringSchedulingIgnoredDuringExecution:
37           - weight: 50
38             preference:
39               matchExpressions:
40                 # 表示node标签存在 disk-type=ssd 或 disk-type=sas
41               - key: disk-type
42                 operator: In
43                 values:
44                 - ssd
45                 - sas

 

运行yaml文件并查看状态

 1 [[email protected] nodeAffinity]# kubectl apply -f node_affinity.yaml 
 2 deployment.apps/node-affinity-deploy created
 3 [[email protected]master nodeAffinity]# 
 4 [[email protected] nodeAffinity]# kubectl get deploy -o wide
 5 NAME                   READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                      SELECTOR
 6 node-affinity-deploy   5/5     5            5           9s    myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp
 7 [[email protected]master nodeAffinity]# 
 8 [[email protected] nodeAffinity]# kubectl get rs -o wide
 9 NAME                             DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                                                      SELECTOR
10 node-affinity-deploy-f9cb9b99b   5         5         5       13s   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp,pod-template-hash=f9cb9b99b
11 [[email protected]master nodeAffinity]# 
12 [[email protected] nodeAffinity]# kubectl get pod -o wide
13 NAME                                   READY   STATUS    RESTARTS   AGE   IP             NODE         NOMINATED NODE   READINESS GATES
14 node-affinity-deploy-f9cb9b99b-8w2nc   1/1     Running   0          17s   10.244.4.10    k8s-node01   <none>           <none>
15 node-affinity-deploy-f9cb9b99b-csk2s   1/1     Running   0          17s   10.244.4.9     k8s-node01   <none>           <none>
16 node-affinity-deploy-f9cb9b99b-g42kq   1/1     Running   0          17s   10.244.4.8     k8s-node01   <none>           <none>
17 node-affinity-deploy-f9cb9b99b-m6xbv   1/1     Running   0          17s   10.244.4.7     k8s-node01   <none>           <none>
18 node-affinity-deploy-f9cb9b99b-mxbdp   1/1     Running   0          17s   10.244.2.253   k8s-node02   <none>           <none>

由上可见,再根据之前打的标签,很容易推断出k8s-node01、k8s-node02都满足必要条件,但当前pod会【优先】调度在k8s-node01节点。

 

Pod亲和性

与节点亲和性一样,当前有Pod亲和性/反亲和性都有两种类型,称为requiredDuringSchedulingIgnoredDuringExecution preferredDuringSchedulingIgnoredDuringExecution,分别表示“硬”与“软”要求。对于硬要求,如果不满足则pod会一直处于Pending状态。

Pod的亲和性与反亲和性是基于Node节点上已经运行pod的标签(而不是节点上的标签)决定的,从而约束哪些节点适合调度你的pod。

规则的形式是:如果X已经运行了一个或多个符合规则Y的pod,则此pod应该在X中运行(如果是反亲和的情况下,则不应该在X中运行)。当然pod必须处在同一名称空间,不然亲和性/反亲和性无作用。从概念上讲,X是一个拓扑域。我们可以使用topologyKey来表示它,topologyKey 的值是node节点标签的键以便系统用来表示这样的拓扑域。当然这里也有个隐藏条件,就是node节点标签的键值相同时,才是在同一拓扑域中;如果只是节点标签名相同,但是值不同,那么也不在同一拓扑域。★★★★★

也就是说:Pod的亲和性/反亲和性调度是根据拓扑域来界定调度的,而不是根据node节点。★★★★★

 

注意事项

1、pod之间亲和性/反亲和性需要大量的处理,这会明显降低大型集群中的调度速度。不建议在大于几百个节点的集群中使用它们。

2、Pod反亲和性要求对节点进行一致的标记。换句话说,集群中的每个节点都必须有一个匹配topologyKey的适当标签。如果某些或所有节点缺少指定的topologyKey标签,可能会导致意外行为。

requiredDuringSchedulingIgnoredDuringExecution中亲和性的一个示例是“将服务A和服务B的Pod放置在同一区域【拓扑域】中,因为它们之间有很多交流”;preferredDuringSchedulingIgnoredDuringExecution中反亲和性的示例是“将此服务的 pod 跨区域【拓扑域】分布”【此时硬性要求是说不通的,因为你可能拥有的 pod 数多于区域数】。

Pod亲和性/反亲和性语法支持以下运算符:In,NotIn,Exists,DoesNotExist

 

原则上,topologyKey可以是任何合法的标签键。但是,出于性能和安全方面的原因,topologyKey有一些限制:

1、对于Pod亲和性,在requiredDuringSchedulingIgnoredDuringExecution和preferredDuringSchedulingIgnoredDuringExecution中topologyKey都不允许为空。

2、对于Pod反亲和性,在requiredDuringSchedulingIgnoredDuringExecution和preferredDuringSchedulingIgnoredDuringExecution中topologyKey也都不允许为空。

3、对于requiredDuringSchedulingIgnoredDuringExecution的pod反亲和性,引入了允许控制器LimitPodHardAntiAffinityTopology来限制topologyKey的kubernet.io/hostname。如果你想让它对自定义拓扑可用,你可以修改许可控制器,或者干脆禁用它。

4、除上述情况外,topologyKey可以是任何合法的标签键。

Pod 间亲和通过 PodSpec 中 affinity 字段下的 podAffinity 字段进行指定。而 pod 间反亲和通过 PodSpec 中 affinity 字段下的 podAntiAffinity 字段进行指定。

Pod亲和性/反亲和性的requiredDuringSchedulingIgnoredDuringExecution所关联的matchExpressions下有多个key列表,那么只有当所有key满足时,才能将pod调度到某个区域【针对Pod硬亲和】。

 

pod亲和性与反亲和性示例

为了更好的演示Pod亲和性与反亲和性,本次示例我们会将k8s-master节点也加入进来进行演示。

准备事项

给node节点打label标签

 1 # 删除已存在标签
 2 kubectl label nodes k8s-node01 cpu-num-
 3 kubectl label nodes k8s-node01 disk-type-
 4 kubectl label nodes k8s-node02 cpu-num-
 5 kubectl label nodes k8s-node02 disk-type-
 6 
 7 
 8 ###  --overwrite覆盖已存在的标签信息
 9 # k8s-master 标签添加
10 kubectl label nodes k8s-master busi-use=www --overwrite
11 kubectl label nodes k8s-master disk-type=ssd --overwrite
12 kubectl label nodes k8s-master busi-db=redis
13 
14 # k8s-node01 标签添加
15 kubectl label nodes k8s-node01 busi-use=www
16 kubectl label nodes k8s-node01 disk-type=sata 
17 kubectl label nodes k8s-node01 busi-db=redis
18 
19 # k8s-node02 标签添加
20 kubectl label nodes k8s-node02 busi-use=www
21 kubectl label nodes k8s-node02 disk-type=ssd
22 kubectl label nodes k8s-node02 busi-db=etcd

 

查询所有节点标签信息

1 [[email protected] ~]# kubectl get node -o wide --show-labels
2 NAME         STATUS   ROLES    AGE   VERSION   INTERNAL-IP    EXTERNAL-IP   OS-IMAGE                KERNEL-VERSION           CONTAINER-RUNTIME   LABELS
3 k8s-master   Ready    master   28d   v1.17.4   172.16.1.110   <none>        CentOS Linux 7 (Core)   3.10.0-1062.el7.x86_64   docker://19.3.8     beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,busi-db=redis,busi-use=www,disk-type=ssd,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-master,kubernetes.io/os=linux,node-role.kubernetes.io/master=
4 k8s-node01   Ready    <none>   28d   v1.17.4   172.16.1.111   <none>        CentOS Linux 7 (Core)   3.10.0-1062.el7.x86_64   docker://19.3.8     beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,busi-db=redis,busi-use=www,disk-type=sata,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node01,kubernetes.io/os=linux
5 k8s-node02   Ready    <none>   28d   v1.17.4   172.16.1.112   <none>        CentOS Linux 7 (Core)   3.10.0-1062.el7.x86_64   docker://19.3.8     beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,busi-db=etcd,busi-use=www,disk-type=ssd,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s-node02,kubernetes.io/os=linux

如上所述:k8s-master添加了disk-type=ssd,busi-db=redis,busi-use=www标签

k8s-node01添加了disk-type=sata,busi-db=redis,busi-use=www标签

k8s-node02添加了disk-type=ssd,busi-db=etcd,busi-use=www标签

通过deployment运行一个pod,或者直接运行一个pod也可以。为后续的Pod亲和性与反亲和性测验做基础。

 1 ### yaml文件
 2 [[email protected] podAffinity]# pwd
 3 /root/k8s_practice/scheduler/podAffinity
 4 [[email protected] podAffinity]# cat web_deploy.yaml 
 5 apiVersion: apps/v1
 6 kind: Deployment
 7 metadata:
 8   name: web-deploy
 9   labels:
10     app: myweb-deploy
11 spec:
12   replicas: 1
13   selector:
14     matchLabels:
15       app: myapp-web
16   template:
17     metadata:
18       labels:
19         app: myapp-web
20         version: v1
21     spec:
22       containers:
23       - name: myapp-pod
24         image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
25         imagePullPolicy: IfNotPresent
26         ports:
27           - containerPort: 80
28 [[email protected]master podAffinity]# 
29 ### 运行yaml文件
30 [[email protected] podAffinity]# kubectl apply -f web_deploy.yaml 
31 deployment.apps/web-deploy created
32 [[email protected]master podAffinity]# 
33 ### 查看pod标签
34 [[email protected] podAffinity]# kubectl get pod -o wide --show-labels
35 NAME                          READY   STATUS    RESTARTS   AGE   IP           NODE         NOMINATED NODE   READINESS GATES   LABELS
36 web-deploy-5ccc9d7c55-kkwst   1/1     Running   0          15m   10.244.2.4   k8s-node02   <none>           <none>            app=myapp-web,pod-template-hash=5ccc9d7c55,version=v1

当前pod在k8s-node02节点;其中pod的标签app=myapp-web,version=v1会在后面pod亲和性/反亲和性示例中使用。

 

pod硬亲和性示例

要运行的yaml文件

 1 [[email protected] podAffinity]# pwd
 2 /root/k8s_practice/scheduler/podAffinity
 3 [[email protected] podAffinity]# cat pod_required_affinity.yaml 
 4 apiVersion: apps/v1
 5 kind: Deployment
 6 metadata:
 7   name: pod-podaffinity-deploy
 8   labels:
 9     app: podaffinity-deploy
10 spec:
11   replicas: 6
12   selector:
13     matchLabels:
14       app: myapp
15   template:
16     metadata:
17       labels:
18         app: myapp
19     spec:
20       # 允许在master节点运行
21       tolerations:
22       - key: node-role.kubernetes.io/master
23         effect: NoSchedule
24       containers:
25       - name: myapp-pod
26         image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
27         imagePullPolicy: IfNotPresent
28         ports:
29           - containerPort: 80
30       affinity:
31         podAffinity:
32           requiredDuringSchedulingIgnoredDuringExecution:
33           - labelSelector:
34               # 由于是Pod亲和性/反亲和性;因此这里匹配规则写的是Pod的标签信息
35               matchExpressions:
36               - key: app
37                 operator: In
38                 values:
39                 - myapp-web 
40             # 拓扑域  若多个node节点具有相同的标签信息【标签键值相同】,则表示这些node节点就在同一拓扑域
41             # 请对比如下两个不同的拓扑域,Pod的调度结果
42             #topologyKey: busi-use
43             topologyKey: disk-type

 

运行yaml文件并查看状态

 1 [[email protected] podAffinity]# kubectl apply -f pod_required_affinity.yaml 
 2 deployment.apps/pod-podaffinity-deploy created
 3 [[email protected]master podAffinity]# 
 4 [[email protected] podAffinity]# kubectl get deploy -o wide
 5 NAME                     READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                      SELECTOR
 6 pod-podaffinity-deploy   6/6     6            6           48s   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp
 7 web-deploy               1/1     1            1           22h   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp-web
 8 [[email protected]master podAffinity]# 
 9 [[email protected] podAffinity]# kubectl get rs -o wide
10 NAME                                DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                                                      SELECTOR
11 pod-podaffinity-deploy-848559bf5b   6         6         6       52s   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp,pod-template-hash=848559bf5b
12 web-deploy-5ccc9d7c55               1         1         1       22h   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp-web,pod-template-hash=5ccc9d7c55
13 [[email protected]master podAffinity]# 
14 [[email protected] podAffinity]# kubectl get pod -o wide
15 NAME                                      READY   STATUS    RESTARTS   AGE   IP             NODE         NOMINATED NODE   READINESS GATES
16 pod-podaffinity-deploy-848559bf5b-8kkwm   1/1     Running   0          54s   10.244.0.80    k8s-master   <none>           <none>
17 pod-podaffinity-deploy-848559bf5b-8s59f   1/1     Running   0          54s   10.244.2.252   k8s-node02   <none>           <none>
18 pod-podaffinity-deploy-848559bf5b-8z4dv   1/1     Running   0          54s   10.244.2.253   k8s-node02   <none>           <none>
19 pod-podaffinity-deploy-848559bf5b-gs7sb   1/1     Running   0          54s   10.244.0.79    k8s-master   <none>           <none>
20 pod-podaffinity-deploy-848559bf5b-sm6nz   1/1     Running   0          54s   10.244.0.78    k8s-master   <none>           <none>
21 pod-podaffinity-deploy-848559bf5b-zbr6v   1/1     Running   0          54s   10.244.2.251   k8s-node02   <none>           <none>
22 web-deploy-5ccc9d7c55-khhrr               1/1     Running   3          22h   10.244.2.245   k8s-node02   <none>           <none>

由上可见,yaml文件中为topologyKey: disk-type;虽然k8s-master、k8s-node01、k8s-node02都有disk-type标签;但是k8s-master和k8s-node02节点的disk-type标签值为ssd;而k8s-node01节点的disk-type标签值为sata。因此k8s-master和k8s-node02节点属于同一拓扑域,Pod只会调度到这两个节点上。

 

pod软亲和性示例

要运行的yaml文件

 1 [[email protected] podAffinity]# pwd
 2 /root/k8s_practice/scheduler/podAffinity
 3 [[email protected]master podAffinity]# 
 4 [[email protected] podAffinity]# cat pod_preferred_affinity.yaml 
 5 apiVersion: apps/v1
 6 kind: Deployment
 7 metadata:
 8   name: pod-podaffinity-deploy
 9   labels:
10     app: podaffinity-deploy
11 spec:
12   replicas: 6
13   selector:
14     matchLabels:
15       app: myapp
16   template:
17     metadata:
18       labels:
19         app: myapp
20     spec:
21       # 允许在master节点运行
22       tolerations:
23       - key: node-role.kubernetes.io/master
24         effect: NoSchedule
25       containers:
26       - name: myapp-pod
27         image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
28         imagePullPolicy: IfNotPresent
29         ports:
30           - containerPort: 80
31       affinity:
32         podAffinity:
33           preferredDuringSchedulingIgnoredDuringExecution:
34           - weight: 100
35             podAffinityTerm:
36               labelSelector:
37                 # 由于是Pod亲和性/反亲和性;因此这里匹配规则写的是Pod的标签信息
38                 matchExpressions:
39                 - key: version
40                   operator: In
41                   values:
42                   - v1
43                   - v2
44               # 拓扑域  若多个node节点具有相同的标签信息【标签键值相同】,则表示这些node节点就在同一拓扑域
45               topologyKey: disk-type

 

运行yaml文件并查看状态

 1 [[email protected] podAffinity]# kubectl apply -f pod_preferred_affinity.yaml 
 2 deployment.apps/pod-podaffinity-deploy created
 3 [[email protected]master podAffinity]# 
 4 [[email protected] podAffinity]# kubectl get deploy -o wide
 5 NAME                     READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                      SELECTOR
 6 pod-podaffinity-deploy   6/6     6            6           75s   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp
 7 web-deploy               1/1     1            1           25h   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp-web
 8 [[email protected]master podAffinity]# 
 9 [[email protected] podAffinity]# kubectl get rs -o wide
10 NAME                                DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                                                      SELECTOR
11 pod-podaffinity-deploy-8474b4b586   6         6         6       79s   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp,pod-template-hash=8474b4b586
12 web-deploy-5ccc9d7c55               1         1         1       25h   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp-web,pod-template-hash=5ccc9d7c55
13 [[email protected]master podAffinity]# 
14 [[email protected] podAffinity]# kubectl get pod -o wide
15 NAME                                      READY   STATUS    RESTARTS   AGE   IP             NODE         NOMINATED NODE   READINESS GATES
16 pod-podaffinity-deploy-8474b4b586-57gxh   1/1     Running   0          83s   10.244.2.4     k8s-node02   <none>           <none>
17 pod-podaffinity-deploy-8474b4b586-kd5l4   1/1     Running   0          83s   10.244.2.3     k8s-node02   <none>           <none>
18 pod-podaffinity-deploy-8474b4b586-mlvv7   1/1     Running   0          83s   10.244.0.84    k8s-master   <none>           <none>
19 pod-podaffinity-deploy-8474b4b586-mtk6r   1/1     Running   0          83s   10.244.0.86    k8s-master   <none>           <none>
20 pod-podaffinity-deploy-8474b4b586-n5jpj   1/1     Running   0          83s   10.244.0.85    k8s-master   <none>           <none>
21 pod-podaffinity-deploy-8474b4b586-q2xdl   1/1     Running   0          83s   10.244.3.22    k8s-node01   <none>           <none>
22 web-deploy-5ccc9d7c55-khhrr               1/1     Running   3          25h   10.244.2.245   k8s-node02   <none>           <none>

由上可见,再根据k8s-master、k8s-node01、k8s-node02的标签信息;很容易推断出Pod会优先调度到k8s-master、k8s-node02节点。

 

pod硬反亲和性示例

要运行的yaml文件

 1 [[email protected] podAffinity]# pwd
 2 /root/k8s_practice/scheduler/podAffinity
 3 [[email protected]master podAffinity]# 
 4 [[email protected] podAffinity]# cat pod_required_AntiAffinity.yaml 
 5 apiVersion: apps/v1
 6 kind: Deployment
 7 metadata:
 8   name: pod-podantiaffinity-deploy
 9   labels:
10     app: podantiaffinity-deploy
11 spec:
12   replicas: 6
13   selector:
14     matchLabels:
15       app: myapp
16   template:
17     metadata:
18       labels:
19         app: myapp
20     spec:
21       # 允许在master节点运行
22       tolerations:
23       - key: node-role.kubernetes.io/master
24         effect: NoSchedule
25       containers:
26       - name: myapp-pod
27         image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
28         imagePullPolicy: IfNotPresent
29         ports:
30           - containerPort: 80
31       affinity:
32         podAntiAffinity:
33           requiredDuringSchedulingIgnoredDuringExecution:
34           - labelSelector:
35               # 由于是Pod亲和性/反亲和性;因此这里匹配规则写的是Pod的标签信息
36               matchExpressions:
37               - key: app
38                 operator: In
39                 values:
40                 - myapp-web
41             # 拓扑域  若多个node节点具有相同的标签信息【标签键值相同】,则表示这些node节点就在同一拓扑域
42             topologyKey: disk-type

 

运行yaml文件并查看状态

 1 [[email protected] podAffinity]# kubectl apply -f pod_required_AntiAffinity.yaml 
 2 deployment.apps/pod-podantiaffinity-deploy created
 3 [[email protected]master podAffinity]#
 4 [[email protected] podAffinity]# kubectl get deploy -o wide
 5 NAME                         READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                      SELECTOR
 6 pod-podantiaffinity-deploy   6/6     6            6           68s   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp
 7 web-deploy                   1/1     1            1           25h   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp-web
 8 [[email protected]master podAffinity]# 
 9 [[email protected] podAffinity]# kubectl get rs -o wide
10 NAME                                    DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                                                      SELECTOR
11 pod-podantiaffinity-deploy-5fb4764b6b   6         6         6       72s   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp,pod-template-hash=5fb4764b6b
12 web-deploy-5ccc9d7c55                   1         1         1       25h   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp-web,pod-template-hash=5ccc9d7c55
13 [[email protected]master podAffinity]# 
14 [[email protected] podAffinity]# kubectl get pod -o wide
15 NAME                                          READY   STATUS    RESTARTS   AGE   IP             NODE         NOMINATED NODE   READINESS GATES
16 pod-podantiaffinity-deploy-5fb4764b6b-b5bzd   1/1     Running   0          75s   10.244.3.28    k8s-node01   <none>           <none>
17 pod-podantiaffinity-deploy-5fb4764b6b-b6qjg   1/1     Running   0          75s   10.244.3.23    k8s-node01   <none>           <none>
18 pod-podantiaffinity-deploy-5fb4764b6b-h262g   1/1     Running   0          75s   10.244.3.27    k8s-node01   <none>           <none>
19 pod-podantiaffinity-deploy-5fb4764b6b-q98gt   1/1     Running   0          75s   10.244.3.24    k8s-node01   <none>           <none>
20 pod-podantiaffinity-deploy-5fb4764b6b-v6kpm   1/1     Running   0          75s   10.244.3.25    k8s-node01   <none>           <none>
21 pod-podantiaffinity-deploy-5fb4764b6b-wtmm6   1/1     Running   0          75s   10.244.3.26    k8s-node01   <none>           <none>
22 web-deploy-5ccc9d7c55-khhrr                   1/1     Running   3          25h   10.244.2.245   k8s-node02   <none>           <none>

由上可见,由于是Pod反亲和测验,再根据k8s-master、k8s-node01、k8s-node02的标签信息;很容易推断出Pod只能调度到k8s-node01节点。

 

pod软反亲和性示例

要运行的yaml文件

 1 [[email protected] podAffinity]# pwd
 2 /root/k8s_practice/scheduler/podAffinity
 3 [[email protected]master podAffinity]# 
 4 [[email protected] podAffinity]# cat pod_preferred_AntiAffinity.yaml 
 5 apiVersion: apps/v1
 6 kind: Deployment
 7 metadata:
 8   name: pod-podantiaffinity-deploy
 9   labels:
10     app: podantiaffinity-deploy
11 spec:
12   replicas: 6
13   selector:
14     matchLabels:
15       app: myapp
16   template:
17     metadata:
18       labels:
19         app: myapp
20     spec:
21       # 允许在master节点运行
22       tolerations:
23       - key: node-role.kubernetes.io/master
24         effect: NoSchedule
25       containers:
26       - name: myapp-pod
27         image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
28         imagePullPolicy: IfNotPresent
29         ports:
30           - containerPort: 80
31       affinity:
32         podAntiAffinity:
33           preferredDuringSchedulingIgnoredDuringExecution:
34           - weight: 100
35             podAffinityTerm:
36               labelSelector:
37                 # 由于是Pod亲和性/反亲和性;因此这里匹配规则写的是Pod的标签信息
38                 matchExpressions:
39                 - key: version
40                   operator: In
41                   values:
42                   - v1
43                   - v2
44               # 拓扑域  若多个node节点具有相同的标签信息【标签键值相同】,则表示这些node节点就在同一拓扑域
45               topologyKey: disk-type

 

运行yaml文件并查看状态

 1 [[email protected] podAffinity]# kubectl apply -f pod_preferred_AntiAffinity.yaml 
 2 deployment.apps/pod-podantiaffinity-deploy created
 3 [[email protected]master podAffinity]# 
 4 [[email protected] podAffinity]# kubectl get deploy -o wide
 5 NAME                         READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                      SELECTOR
 6 pod-podantiaffinity-deploy   6/6     6            6           9s    myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp
 7 web-deploy                   1/1     1            1           26h   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp-web
 8 [[email protected]master podAffinity]# 
 9 [[email protected] podAffinity]# kubectl get rs -o wide
10 NAME                                    DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                                                      SELECTOR
11 pod-podantiaffinity-deploy-54d758ddb4   6         6         6       13s   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp,pod-template-hash=54d758ddb4
12 web-deploy-5ccc9d7c55                   1         1         1       26h   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp-web,pod-template-hash=5ccc9d7c55
13 [[email protected]master podAffinity]# 
14 [[email protected] podAffinity]# kubectl get pod -o wide
15 NAME                                          READY   STATUS    RESTARTS   AGE   IP             NODE         NOMINATED NODE   READINESS GATES
16 pod-podantiaffinity-deploy-54d758ddb4-58t9p   1/1     Running   0          17s   10.244.3.31    k8s-node01   <none>           <none>
17 pod-podantiaffinity-deploy-54d758ddb4-9ntd7   1/1     Running   0          17s   10.244.3.32    k8s-node01   <none>           <none>
18 pod-podantiaffinity-deploy-54d758ddb4-9wr6p   1/1     Running   0          17s   10.244.2.5     k8s-node02   <none>           <none>
19 pod-podantiaffinity-deploy-54d758ddb4-gnls4   1/1     Running   0          17s   10.244.3.30    k8s-node01   <none>           <none>
20 pod-podantiaffinity-deploy-54d758ddb4-jlftn   1/1     Running   0          17s   10.244.3.29    k8s-node01   <none>           <none>
21 pod-podantiaffinity-deploy-54d758ddb4-mvplv   1/1     Running   0          17s   10.244.0.87    k8s-master   <none>           <none>
22 web-deploy-5ccc9d7c55-khhrr                   1/1     Running   3          26h   10.244.2.245   k8s-node02   <none>           <none>

由上可见,由于是Pod反亲和测验,再根据k8s-master、k8s-node01、k8s-node02的标签信息;很容易推断出Pod会优先调度到k8s-node01节点。

 

pod亲和性与反亲和性联合示例

要运行的yaml文件

 1 [[email protected] podAffinity]# pwd
 2 /root/k8s_practice/scheduler/podAffinity
 3 [[email protected]master podAffinity]# 
 4 [[email protected] podAffinity]# cat pod_podAffinity_all.yaml 
 5 apiVersion: apps/v1
 6 kind: Deployment
 7 metadata:
 8   name: pod-podaffinity-all-deploy
 9   labels:
10     app: podaffinity-all-deploy
11 spec:
12   replicas: 6
13   selector:
14     matchLabels:
15       app: myapp
16   template:
17     metadata:
18       labels:
19         app: myapp
20     spec:
21       # 允许在master节点运行
22       tolerations:
23       - key: node-role.kubernetes.io/master
24         effect: NoSchedule
25       containers:
26       - name: myapp-pod
27         image: registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1
28         imagePullPolicy: IfNotPresent
29         ports:
30           - containerPort: 80
31       affinity:
32         podAffinity:
33           requiredDuringSchedulingIgnoredDuringExecution:
34           - labelSelector:
35               # 由于是Pod亲和性/反亲和性;因此这里匹配规则写的是Pod的标签信息
36               matchExpressions:
37               - key: app
38                 operator: In
39                 values:
40                 - myapp-web
41             # 拓扑域  若多个node节点具有相同的标签信息【标签键值相同】,则表示这些node节点就在同一拓扑域
42             topologyKey: disk-type
43         podAntiAffinity:
44           preferredDuringSchedulingIgnoredDuringExecution:
45           - weight: 100
46             podAffinityTerm:
47               labelSelector:
48                 matchExpressions:
49                 - key: version
50                   operator: In
51                   values:
52                   - v1
53                   - v2
54               topologyKey: busi-db

 

运行yaml文件并查看状态

 1 [[email protected] podAffinity]# kubectl apply -f pod_podAffinity_all.yaml 
 2 deployment.apps/pod-podaffinity-all-deploy created
 3 [[email protected]master podAffinity]# 
 4 [[email protected] podAffinity]# kubectl get deploy -o wide
 5 NAME                         READY   UP-TO-DATE   AVAILABLE   AGE   CONTAINERS   IMAGES                                                      SELECTOR
 6 pod-podaffinity-all-deploy   6/6     6            1           5s    myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp
 7 web-deploy                   1/1     1            1           28h   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp-web
 8 [[email protected]master podAffinity]# 
 9 [[email protected] podAffinity]# kubectl get rs -o wide
10 NAME                                    DESIRED   CURRENT   READY   AGE   CONTAINERS   IMAGES                                                      SELECTOR
11 pod-podaffinity-all-deploy-5ddbf9cbf8   6         6         6       10s   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp,pod-template-hash=5ddbf9cbf8
12 web-deploy-5ccc9d7c55                   1         1         1       28h   myapp-pod    registry.cn-beijing.aliyuncs.com/google_registry/myapp:v1   app=myapp-web,pod-template-hash=5ccc9d7c55
13 [[email protected]master podAffinity]# 
14 [[email protected] podAffinity]# kubectl get pod -o wide
15 NAME                                          READY   STATUS    RESTARTS   AGE   IP             NODE         NOMINATED NODE   READINESS GATES
16 pod-podaffinity-all-deploy-5ddbf9cbf8-5w5b7   1/1     Running   0          15s   10.244.0.91    k8s-master   <none>           <none>
17 pod-podaffinity-all-deploy-5ddbf9cbf8-j57g9   1/1     Running   0          15s   10.244.0.90    k8s-master   <none>           <none>
18 pod-podaffinity-all-deploy-5ddbf9cbf8-kwz6w   1/1     Running   0          15s   10.244.0.92    k8s-master   <none>           <none>
19 pod-podaffinity-all-deploy-5ddbf9cbf8-l8spj   1/1     Running   0          15s   10.244.2.6     k8s-node02   <none>           <none>
20 pod-podaffinity-all-deploy-5ddbf9cbf8-lf22c   1/1     Running   0          15s   10.244.0.89    k8s-master   <none>           <none>
21 pod-podaffinity-all-deploy-5ddbf9cbf8-r2fgl   1/1     Running   0          15s   10.244.0.88    k8s-master   <none>           <none>
22 web-deploy-5ccc9d7c55-khhrr                   1/1     Running   3          28h   10.244.2.245   k8s-node02   <none>           <none>

由上可见,根据k8s-master、k8s-node01、k8s-node02的标签信息;很容易推断出Pod只能调度到k8s-master、k8s-node02节点,且会优先调度到k8s-master节点。

 

相关阅读

1、官网:将Pods分配给节点

2、Kubernetes K8S调度器kube-scheduler详解

完毕!

 


 

 

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