这篇文章给大家分享的是有关docker中资源指标API及自定义指标API的示例分析的内容。小编觉得挺实用的,因此分享给大家做个参考,一起跟随小编过来看看吧。
以前是用heapster来收集资源指标才能看,现在heapster要废弃了。
从k8s v1.8开始后,引入了新的功能,即把资源指标引入api。
资源指标:metrics-server
自定义指标: prometheus,k8s-prometheus-adapter
因此,新一代架构:
1) 核心指标流水线:由kubelet、metrics-server以及由API server提供的api组成;cpu累计利用率、内存实时利用率、pod的资源占用率及容器的磁盘占用率
2) 监控流水线:用于从系统收集各种指标数据并提供终端用户、存储系统以及HPA,他们包含核心指标以及许多非核心指标。非核心指标不能被k8s所解析。
metrics-server是个api server,仅仅收集cpu利用率、内存利用率等。
[root@master ~]# kubectl api-versions
admissionregistration.k8s.io/v1beta1
apiextensions.k8s.io/v1beta1
apiregistration.k8s.io/v1
apiregistration.k8s.io/v1beta1
apps/v1
apps/v1beta1
apps/v1beta2
authentication.k8s.io/v1
authentication.k8s.io/v1beta1
authorization.k8s.io/v1
访问 https://github.com/kubernetes/kubernetes/tree/master/cluster/addons/metrics-server
把文件下载到本地目录,,注意,一定要到和自己k8s集群版本一致目录里面下载,比如我的k8s 是v1.11.2。否则安装后metrics的pod运行不起来。
[root@master metrics-server]# cd kubernetes-1.11.2/cluster/addons/metrics-server
[root@master metrics-server]# ls
auth-delegator.yaml metrics-apiservice.yaml metrics-server-service.yaml
auth-reader.yaml metrics-server-deployment.yaml resource-reader.yaml
注意:需要修改的地方:
metrics-server-deployment.yaml
# - --source=kubernetes.summary_api:''
- --source=kubernetes.summary_api:https://kubernetes.default?kubeletHttps=true&kubeletPort=10250&insecure=true
resource-reader.yaml
resources:
- pods
- nodes
- namespaces
- nodes/stats #新加
[root@master metrics-server]# kubectl apply -f ./
clusterrolebinding.rbac.authorization.k8s.io/metrics-server:system:auth-delegator created
rolebinding.rbac.authorization.k8s.io/metrics-server-auth-reader created
apiservice.apiregistration.k8s.io/v1beta1.metrics.k8s.io created
serviceaccount/metrics-server created
configmap/metrics-server-config created
deployment.extensions/metrics-server-v0.3.1 created
service/metrics-server created
clusterrole.rbac.authorization.k8s.io/system:metrics-server created
clusterrolebinding.rbac.authorization.k8s.io/system:metrics-server created
[root@master metrics-server]# kubectl get pods -n kube-system -o wide
NAME READY STATUS RESTARTS AGE IP NODE
metrics-server-v0.2.1-fd596d746-c7x6q 2/2 Running 0 1m 10.244.2.49 node2
[root@master metrics-server]# kubectl api-versions
metrics.k8s.io/v1beta1
看到api-version里面有metrics了。
[root@master ~]# kubectl proxy --port=8080
Starting to serve on 127.0.0.1:8080
[root@master ~]# curl http://localhost:8080/apis/metrics.k8s.io/v1beta1
{
"kind": "APIResourceList",
"apiVersion": "v1",
"groupVersion": "metrics.k8s.io/v1beta1",
"resources": [
{
"name": "nodes",
"singularName": "",
"namespaced": false,
"kind": "NodeMetrics",
"verbs": [
"get",
"list"
]
},
{
"name": "pods",
"singularName": "",
"namespaced": true,
"kind": "PodMetrics",
"verbs": [
"get",
"list"
]
}
]
[root@master metrics-server]# curl http://localhost:8080/apis/metrics.k8s.io/v1beta1/pods
{
"kind": "PodMetricsList",
"apiVersion": "metrics.k8s.io/v1beta1",
"metadata": {
"selfLink": "/apis/metrics.k8s.io/v1beta1/pods"
},
"items": [
{
"metadata": {
"name": "pod1",
"namespace": "dev",
"selfLink": "/apis/metrics.k8s.io/v1beta1/namespaces/dev/pods/pod1",
"creationTimestamp": "2018-10-15T09:26:57Z"
},
"timestamp": "2018-10-15T09:26:00Z",
"window": "1m0s",
"containers": [
{
"name": "myapp",
"usage": {
"cpu": "0",
"memory": "2940Ki"
}
}
]
},
{
"metadata": {
"name": "rook-ceph-osd-0-b9b94dc6c-ffs8z",
"namespace": "rook-ceph",
"selfLink": "/apis/metrics.k8s.io/v1beta1/namespaces/rook-ceph/pods/rook-ceph-osd-0-b9b94dc6c-ffs8z",
"creationTimestamp": "2018-10-15T09:26:57Z"
},
"timestamp": "2018-10-15T09:26:00Z",
"window": "1m0s",
"containers": [
{
[root@master metrics-server]# curl http://localhost:8080/apis/metrics.k8s.io/v1beta1/nodes
{
"kind": "NodeMetricsList",
"apiVersion": "metrics.k8s.io/v1beta1",
"metadata": {
"selfLink": "/apis/metrics.k8s.io/v1beta1/nodes"
},
"items": [
{
"metadata": {
"name": "node2",
"selfLink": "/apis/metrics.k8s.io/v1beta1/nodes/node2",
"creationTimestamp": "2018-10-15T09:27:26Z"
},
"timestamp": "2018-10-15T09:27:00Z",
"window": "1m0s",
"usage": {
"cpu": "90m",
"memory": "1172044Ki"
}
},
{
"metadata": {
"name": "master",
"selfLink": "/apis/metrics.k8s.io/v1beta1/nodes/master",
"creationTimestamp": "2018-10-15T09:27:26Z"
},
"timestamp": "2018-10-15T09:27:00Z",
"window": "1m0s",
"usage": {
"cpu": "186m",
"memory": "1582972Ki"
}
},
{
"metadata": {
"name": "node1",
"selfLink": "/apis/metrics.k8s.io/v1beta1/nodes/node1",
"creationTimestamp": "2018-10-15T09:27:26Z"
},
"timestamp": "2018-10-15T09:27:00Z",
"window": "1m0s",
"usage": {
"cpu": "68m",
"memory": "1079332Ki"
}
}
]
}[root@master metrics-server]#
看到iterms里面有数据了,说明可以采集各节点和pod里面的资源使用情况了。注意,如果你看不到就多等一会,如果等了很长的时间,iterm里面还是空,那么就看看metrics容器里面的日志是不是有报错。查看日志的方法为:
[root@master metrics-server]#kubectl get pods -n kube-system
NAME READY STATUS RESTARTS AGE
metrics-server-v0.2.1-84678c956-jdtr5 2/2 Running 0 14m
[root@master metrics-server]# kubectl logs metrics-server-v0.2.1-84678c956-jdtr5 -c metrics-server -n kube-system
-8r6lz
I1015 09:26:57.117323 1 reststorage.go:93] No metrics for pod rook-ceph/rook-ceph-osd-prepare-node1-8r6lz
I1015 09:26:57.117336 1 reststorage.go:140] No metrics for container rook-ceph-osd in pod rook-ceph/rook-ceph-osd-prepare-node2-vnr97
I1015 09:26:57.117347 1 reststorage.go:93] No metrics for pod rook-ceph/rook-ceph-osd-prepare-node2-vnr97
这样,kubectl top命令就能使用了:
[root@master ~]# kubectl top nodes
NAME CPU(cores) CPU% MEMORY(bytes) MEMORY%
master 131m 3% 1716Mi 46%
node1 68m 1% 1169Mi 31%
node2 96m 2% 1236Mi 33%
[root@master manifests]# kubectl top pods
NAME CPU(cores) MEMORY(bytes)
myapp-deploy-69b47bc96d-dfpvp 0m 2Mi
myapp-deploy-69b47bc96d-g9kkz 0m 2Mi
[root@master manifests]# kubectl top pods -n kube-system
NAME CPU(cores) MEMORY(bytes)
canal-4h3ww 11m 49Mi
canal-6tdxn 11m 49Mi
canal-z2tp4 11m 43Mi
coredns-78fcdf6894-2l2cf 1m 9Mi
coredns-78fcdf6894-dkkfq 1m 10Mi
etcd-master 14m 242Mi
kube-apiserver-master 26m 527Mi
kube-controller-manager-master 20m 68Mi
kube-flannel-ds-amd64-6zqzr 2m 15Mi
kube-flannel-ds-amd64-7qtcl 2m 17Mi
kube-flannel-ds-amd64-kpctn 2m 18Mi
kube-proxy-9snbs 2m 16Mi
kube-proxy-psmxj 2m 18Mi
kube-proxy-tc8g6 2m 17Mi
kube-scheduler-master 6m 16Mi
kubernetes-dashboard-767dc7d4d-4mq9z 0m 12Mi
metrics-server-v0.2.1-84678c956-jdtr5 0m 29Mi
大家看到,我们的metrics已经可以正常工作了。不过,metrics只能监控cpu和内存,对于其他指标如用户自定义的监控指标,metrics就无法监控到了。这时就需要另外一个组件叫prometheus。
prometheus的部署非常麻烦。
node_exporter是agent;
PromQL相当于sql语句来查询数据;
k8s-prometheus-adapter:prometheus是不能直接解析k8s的指标的,需要借助k8s-prometheus-adapter转换成api
kube-state-metrics是用来整合数据的。
下面开始部署。
访问 https://github.com/ikubernetes/k8s-prom
[root@master pro]# git clone https://github.com/iKubernetes/k8s-prom.git
先创建一个叫prom的名称空间:
[root@master k8s-prom]# kubectl apply -f namespace.yaml
namespace/prom created
部署node_exporter:
[root@master k8s-prom]# cd node_exporter/
[root@master node_exporter]# ls
node-exporter-ds.yaml node-exporter-svc.yaml
[root@master node_exporter]# kubectl apply -f .
daemonset.apps/prometheus-node-exporter created
service/prometheus-node-exporter created
[root@master node_exporter]# kubectl get pods -n prom
NAME READY STATUS RESTARTS AGE
prometheus-node-exporter-dmmjj 1/1 Running 0 7m
prometheus-node-exporter-ghz2l 1/1 Running 0 7m
prometheus-node-exporter-zt2lw 1/1 Running 0 7m
部署prometheus:
[root@master k8s-prom]# cd prometheus/
[root@master prometheus]# ls
prometheus-cfg.yaml prometheus-deploy.yaml prometheus-rbac.yaml prometheus-svc.yaml
[root@master prometheus]# kubectl apply -f .
configmap/prometheus-config created
deployment.apps/prometheus-server created
clusterrole.rbac.authorization.k8s.io/prometheus created
serviceaccount/prometheus created
clusterrolebinding.rbac.authorization.k8s.io/prometheus created
service/prometheus created
看prom名称空间中的所有资源:
[root@master prometheus]# kubectl get all -n prom
NAME READY STATUS RESTARTS AGE
pod/prometheus-node-exporter-dmmjj 1/1 Running 0 10m
pod/prometheus-node-exporter-ghz2l 1/1 Running 0 10m
pod/prometheus-node-exporter-zt2lw 1/1 Running 0 10m
pod/prometheus-server-65f5d59585-6l8m8 1/1 Running 0 55s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/prometheus NodePort 10.111.127.64 <none> 9090:30090/TCP 56s
service/prometheus-node-exporter ClusterIP None <none> 9100/TCP 10m
NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE
daemonset.apps/prometheus-node-exporter 3 3 3 3 3 <none> 10m
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
deployment.apps/prometheus-server 1 1 1 1 56s
NAME DESIRED CURRENT READY AGE
replicaset.apps/prometheus-server-65f5d59585 1 1 1 56s
上面我们看到通过NodePorts的方式,可以通过宿主机的30090端口,来访问prometheus容器里面的应用。
最好挂载个pvc的存储,要不这些监控数据过一会就没了。
部署kube-state-metrics,用来整合数据:
[root@master k8s-prom]# cd kube-state-metrics/
[root@master kube-state-metrics]# ls
kube-state-metrics-deploy.yaml kube-state-metrics-rbac.yaml kube-state-metrics-svc.yaml
[root@master kube-state-metrics]# kubectl apply -f .
deployment.apps/kube-state-metrics created
serviceaccount/kube-state-metrics created
clusterrole.rbac.authorization.k8s.io/kube-state-metrics created
clusterrolebinding.rbac.authorization.k8s.io/kube-state-metrics created
service/kube-state-metrics created
[root@master kube-state-metrics]# kubectl get all -n prom
NAME READY STATUS RESTARTS AGE
pod/kube-state-metrics-58dffdf67d-v9klh 1/1 Running 0 14m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kube-state-metrics ClusterIP 10.111.41.139 <none> 8080/TCP 14m
部署k8s-prometheus-adapter,这个需要自制证书:
[root@master k8s-prometheus-adapter]# cd /etc/kubernetes/pki/
[root@master pki]# (umask 077; openssl genrsa -out serving.key 2048)
Generating RSA private key, 2048 bit long modulus
...........................................................................................+++
...............+++
e is 65537 (0x10001)
证书请求:
[root@master pki]# openssl req -new -key serving.key -out serving.csr -subj "/CN=serving"
开始签证:
[root@master pki]# openssl x509 -req -in serving.csr -CA ./ca.crt -CAkey ./ca.key -CAcreateserial -out serving.crt -days 3650
Signature ok
subject=/CN=serving
Getting CA Private Key
创建加密的配置文件:
[root@master pki]# kubectl create secret generic cm-adapter-serving-certs --from-file=serving.crt=./serving.crt --from-file=serving.key=./serving.key -n prom
secret/cm-adapter-serving-certs created
注:cm-adapter-serving-certs是custom-metrics-apiserver-deployment.yaml文件里面的名字。
[root@master pki]# kubectl get secrets -n prom
NAME TYPE DATA AGE
cm-adapter-serving-certs Opaque 2 51s
default-token-knsbg kubernetes.io/service-account-token 3 4h
kube-state-metrics-token-sccdf kubernetes.io/service-account-token 3 3h
prometheus-token-nqzbz kubernetes.io/service-account-token 3 3h
部署k8s-prometheus-adapter:
[root@master k8s-prom]# cd k8s-prometheus-adapter/
[root@master k8s-prometheus-adapter]# ls
custom-metrics-apiserver-auth-delegator-cluster-role-binding.yaml custom-metrics-apiserver-service.yaml
custom-metrics-apiserver-auth-reader-role-binding.yaml custom-metrics-apiservice.yaml
custom-metrics-apiserver-deployment.yaml custom-metrics-cluster-role.yaml
custom-metrics-apiserver-resource-reader-cluster-role-binding.yaml custom-metrics-resource-reader-cluster-role.yaml
custom-metrics-apiserver-service-account.yaml hpa-custom-metrics-cluster-role-binding.yaml
由于k8s v1.11.2和k8s-prometheus-adapter最新版不兼容,解决办法就是访问https://github.com/DirectXMan12/k8s-prometheus-adapter/tree/master/deploy/manifests下载最新版的custom-metrics-apiserver-deployment.yaml文件,并把里面的namespace的名字改成prom;同时还要下载custom-metrics-config-map.yaml文件到本地来,并把里面的namespace的名字改成prom。
[root@master k8s-prometheus-adapter]# kubectl apply -f .
clusterrolebinding.rbac.authorization.k8s.io/custom-metrics:system:auth-delegator created
rolebinding.rbac.authorization.k8s.io/custom-metrics-auth-reader created
deployment.apps/custom-metrics-apiserver created
clusterrolebinding.rbac.authorization.k8s.io/custom-metrics-resource-reader created
serviceaccount/custom-metrics-apiserver created
service/custom-metrics-apiserver created
apiservice.apiregistration.k8s.io/v1beta1.custom.metrics.k8s.io created
clusterrole.rbac.authorization.k8s.io/custom-metrics-server-resources created
clusterrole.rbac.authorization.k8s.io/custom-metrics-resource-reader created
clusterrolebinding.rbac.authorization.k8s.io/hpa-controller-custom-metrics created
[root@master k8s-prometheus-adapter]# kubectl get all -n prom
NAME READY STATUS RESTARTS AGE
pod/custom-metrics-apiserver-65f545496-64lsz 1/1 Running 0 6m
pod/kube-state-metrics-58dffdf67d-v9klh 1/1 Running 0 4h
pod/prometheus-node-exporter-dmmjj 1/1 Running 0 4h
pod/prometheus-node-exporter-ghz2l 1/1 Running 0 4h
pod/prometheus-node-exporter-zt2lw 1/1 Running 0 4h
pod/prometheus-server-65f5d59585-6l8m8 1/1 Running 0 4h
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/custom-metrics-apiserver ClusterIP 10.103.87.246 <none> 443/TCP 36m
service/kube-state-metrics ClusterIP 10.111.41.139 <none> 8080/TCP 4h
service/prometheus NodePort 10.111.127.64 <none> 9090:30090/TCP 4h
service/prometheus-node-exporter ClusterIP None <none> 9100/TCP 4h
NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE
daemonset.apps/prometheus-node-exporter 3 3 3 3 3 <none> 4h
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
deployment.apps/custom-metrics-apiserver 1 1 1 1 36m
deployment.apps/kube-state-metrics 1 1 1 1 4h
deployment.apps/prometheus-server 1 1 1 1 4h
NAME DESIRED CURRENT READY AGE
replicaset.apps/custom-metrics-apiserver-5f6b4d857d 0 0 0 36m
replicaset.apps/custom-metrics-apiserver-65f545496 1 1 1 6m
replicaset.apps/custom-metrics-apiserver-86ccf774d5 0 0 0 17m
replicaset.apps/kube-state-metrics-58dffdf67d 1 1 1 4h
replicaset.apps/prometheus-server-65f5d59585 1 1 1 4h
最终看到prom名称空间里面的所有资源都是running状态了。
[root@master k8s-prometheus-adapter]# kubectl api-versions
custom.metrics.k8s.io/v1beta1
可以看到custom.metrics.k8s.io/v1beta1这个api了。
开个代理:
[root@master k8s-prometheus-adapter]# kubectl proxy --port=8080
可以看到指标数据了:
[root@master pki]# curl http://localhost:8080/apis/custom.metrics.k8s.io/v1beta1/
{
"name": "pods/ceph_rocksdb_submit_transaction_sync",
"singularName": "",
"namespaced": true,
"kind": "MetricValueList",
"verbs": [
"get"
]
},
{
"name": "jobs.batch/kube_deployment_created",
"singularName": "",
"namespaced": true,
"kind": "MetricValueList",
"verbs": [
"get"
]
},
{
"name": "jobs.batch/kube_pod_owner",
"singularName": "",
"namespaced": true,
"kind": "MetricValueList",
"verbs": [
"get"
]
},
下面我们就可以愉快的创建HPA了(水平Pod自动伸缩)。
另外,prometheus还可以和grafana整合。如下步骤。
先下载文件grafana.yaml,访问https://github.com/kubernetes/heapster/blob/master/deploy/kube-config/influxdb/grafana.yaml
[root@master pro]# wget
修改grafana.yaml文件内容:
把namespace: kube-system改成prom,有两处;
把env里面的下面两个注释掉:
- name: INFLUXDB_HOST
value: monitoring-influxdb
在最有一行加个type: NodePort
ports:
- port: 80
targetPort: 3000
selector:
k8s-app: grafana
type: NodePort
[root@master pro]# kubectl apply -f grafana.yaml
deployment.extensions/monitoring-grafana created
service/monitoring-grafana created
[root@master pro]# kubectl get pods -n prom
NAME READY STATUS RESTARTS AGE
monitoring-grafana-ffb4d59bd-gdbsk 1/1 Running 0 5s
看到grafana这个pod运行起来了。
[root@master pro]# kubectl get svc -n prom
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
monitoring-grafana NodePort 10.106.164.205 <none> 80:32659/TCP 19m
我们可以访问宿主机ip: http://172.16.1.100:32659
然后,就能从界面上看到相应的数据了。
登录下面的网站下载个grafana监控k8s-prometheus的模板:
然后再grafana的界面中导入上面下载的模板:
导入模板之后,就能看到监控数据了:
当pod压力大了,会根据负载自动扩展Pod个数以均匀压力。
目前,HPA只支持两个版本,v1版本只支持核心指标的定义(只能根据cpu利用率的指标进行pod的扩展);
[root@master pro]# kubectl explain hpa.spec.scaleTargetRef
scaleTargetRef:表示基于什么指标来计算pod伸缩的标准
[root@master pro]# kubectl api-versions |grep auto
autoscaling/v1
autoscaling/v2beta1
上面看到分别支持hpav1和hpav2。
下面我们用命令行的方式重新创建一个带有资源限制的pod myapp:
[root@master ~]# kubectl run myapp --image=ikubernetes/myapp:v1 --replicas=1 --requests='cpu=50m,memory=256Mi' --limits='cpu=50m,memory=256Mi' --labels='app=myapp' --expose --port=80
service/myapp created
deployment.apps/myapp created
[root@master ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
myapp-6985749785-fcvwn 1/1 Running 0 58s
下面我们让myapp 这个pod能自动水平扩展,用kubectl autoscale,其实就是指明HPA控制器的。
[root@master ~]# kubectl autoscale deployment myapp --min=1 --max=8 --cpu-percent=60
horizontalpodautoscaler.autoscaling/myapp autoscaled
--min:表示最小扩展pod的个数
--max:表示最多扩展pod的个数
--cpu-percent:cpu利用率
[root@master ~]# kubectl get hpa
NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE
myapp Deployment/myapp 0%/60% 1 8 1 4m
[root@master ~]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
myapp ClusterIP 10.105.235.197 <none> 80/TCP 19
下面我们把service改成NodePort的方式:
[root@master ~]# kubectl patch svc myapp -p '{"spec":{"type": "NodePort"}}'
service/myapp patched
[root@master ~]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
myapp NodePort 10.105.235.197 <none> 80:31990/TCP 22m
[root@master ~]# yum install httpd-tools #主要是为了安装ab压测工具
[root@master ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE
myapp-6985749785-fcvwn 1/1 Running 0 25m 10.244.2.84 node2
开始用ab工具压测
[root@master ~]# ab -c 1000 -n 5000000 http://172.16.1.100:31990/index.html
This is ApacheBench, Version 2.3 <$Revision: 1430300 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/
Benchmarking 172.16.1.100 (be patient)
多等一会,会看到pods的cpu利用率为98%,需要扩展为2个pod了:
[root@master ~]# kubectl describe hpa
resource cpu on pods (as a percentage of request): 98% (49m) / 60%
Deployment pods: 1 current / 2 desired
[root@master ~]# kubectl top pods
NAME CPU(cores) MEMORY(bytes)
myapp-6985749785-fcvwn 49m (我们设置的总cpu是50m) 3Mi
[root@master ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE
myapp-6985749785-fcvwn 1/1 Running 0 32m 10.244.2.84 node2
myapp-6985749785-sr4qv 1/1 Running 0 2m 10.244.1.105 node1
上面我们看到已经自动扩展为2个pod了,再等一会,随着cpu压力的上升,还会看到自动扩展为4个或更多的pod:
[root@master ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE
myapp-6985749785-2mjrd 1/1 Running 0 1m 10.244.1.107 node1
myapp-6985749785-bgz6p 1/1 Running 0 1m 10.244.1.108 node1
myapp-6985749785-fcvwn 1/1 Running 0 35m 10.244.2.84 node2
myapp-6985749785-sr4qv 1/1 Running 0 5m 10.244.1.105 node1
等压测一停止,pod个数还会收缩为正常个数的。
上面我们用的是hpav1来做的水平pod自动扩展的功能,我们前面也说过,hpa v1版本只能根据cpu利用率括水平自动扩展pod。
下面我们介绍一下hpa v2的功能,它可以根据自定义指标利用率来水平扩展pod。
在使用hpa v2版本前,我们先把前面创建的hpa v1版本删除了,以免和我们测试的hpa v2版本冲突:
[root@master hpa]# kubectl delete hpa myapp
horizontalpodautoscaler.autoscaling "myapp" deleted
好了,下面我们创建一个hpa v2:
[root@master hpa]# cat hpa-v2-demo.yaml
apiVersion: autoscaling/v2beta1 #从这可以看出是hpa v2版本
kind: HorizontalPodAutoscaler
metadata:
name: myapp-hpa-v2
spec:
scaleTargetRef: #根据什么指标来做评估压力
apiVersion: apps/v1 #对谁来做自动扩展
kind: Deployment
name: myapp
minReplicas: 1 #最少副本数量
maxReplicas: 10
metrics: #表示依据哪些指标来进行评估
- type: Resource #表示基于资源进行评估
resource:
name: cpu
targetAverageUtilization: 55 #表示pod cpu使用率超过55%,就自动水平扩展pod个数
- type: Resource
resource:
name: memory #我们知道hpa v1版本只能根据cpu来进行评估,而到了我们的hpa v2版本就可以根据内存来进行评估了
targetAverageValue: 50Mi #表示pod内存使用超过50M,就自动水平扩展pod个数
[root@master hpa]# kubectl apply -f hpa-v2-demo.yaml
horizontalpodautoscaler.autoscaling/myapp-hpa-v2 created
[root@master hpa]# kubectl get hpa
NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE
myapp-hpa-v2 Deployment/myapp 3723264/50Mi, 0%/55% 1 10 1 37s
我们看到现在只有一个pod
[root@master hpa]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE
myapp-6985749785-fcvwn 1/1 Running 0 57m 10.244.2.84 node2
开始压测:
[root@master ~]# ab -c 100 -n 5000000 http://172.16.1.100:31990/index.html
看hpa v2的检测情况:
[root@master hpa]# kubectl describe hpa
Metrics: ( current / target )
resource memory on pods: 3756032 / 50Mi
resource cpu on pods (as a percentage of request): 82% (41m) / 55%
Min replicas: 1
Max replicas: 10
Deployment pods: 1 current / 2 desired
[root@master hpa]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE
myapp-6985749785-8frq4 1/1 Running 0 1m 10.244.1.109 node1
myapp-6985749785-fcvwn 1/1 Running 0 1h 10.244.2.84 node2
看到自动扩展出了2个Pod。等压测一停止,pod个数还会收缩为正常个数的。
将来我们不光可以用hpa v2,根据cpu和内存使用率进行伸缩Pod个数,还可以根据http并发量等。
比如下面的:
[root@master hpa]# cat hpa-v2-custom.yaml
apiVersion: autoscaling/v2beta1 #从这可以看出是hpa v2版本
kind: HorizontalPodAutoscaler
metadata:
name: myapp-hpa-v2
spec:
scaleTargetRef: #根据什么指标来做评估压力
apiVersion: apps/v1 #对谁来做自动扩展
kind: Deployment
name: myapp
minReplicas: 1 #最少副本数量
maxReplicas: 10
metrics: #表示依据哪些指标来进行评估
- type: Pods #表示基于资源进行评估
pods:
metricName: http_requests#自定义的资源指标
targetAverageValue: 800m #m表示个数,表示并发数800
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原文链接:http://blog.itpub.net/28916011/viewspace-2216340/