k8s以StatefulSet方式部署zookeeper集群：
zookeeper-headless.yaml
apiVersion: v1kind: Servicemetadata:
name: zk-hs labels:
app: zkspec:
selector:
app: zk ports:
- port: 2888
name: server - port: 3888
name: leader-election clusterIP: None
---apiVersion: v1kind: Servicemetadata:
name: zk-cs labels:
app: zkspec:
selector:
app: zk ports:
- port: 2181
name: client
---apiVersion: v1kind: ConfigMapmetadata:
name: zk-configdata:
ensemble: "zk-0;zk-1;zk-2"
replicas: "3"
jvm.heap: "512M"
tick: "2000"
init: "10"
sync: "5"
client.cnxns: "60"
snap.retain: "3"
purge.interval: "1"
---apiVersion: policy/v1beta1kind: PodDisruptionBudgetmetadata:
name: zk-pdbspec:
selector:
matchLabels:
app: zk minAvailable: 2
---apiVersion: apps/v1kind: StatefulSetmetadata:
name: zkspec:
selector:
matchLabels:
app: zk serviceName: zk-hs replicas: 3
updateStrategy:
type: RollingUpdate podManagementPolicy: OrderedReady template:
metadata:
labels:
app: zk spec:
affinity:
podAntiAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- labelSelector:
matchExpressions:
- key: "app"
operator: In values:
- zk topologyKey: "kubernetes.io/hostname"
containers:
- name: zk image: /xianlu/k8szk:v2 imagePullPolicy: IfNotPresent ports:
- containerPort: 2181
name: client - containerPort: 2888
name: server - containerPort: 3888
name: leader-election resources:
requests:
cpu: "500m"
memory: "512Mi"
env:
- name : ZK_ENSEMBLE valueFrom:
configMapKeyRef:
name: zk-config key: ensemble - name : ZK_REPLICAS valueFrom:
configMapKeyRef:
name: zk-config key: replicas - name : ZK_HEAP_SIZE valueFrom:
configMapKeyRef:
name: zk-config key: jvm.heap - name : ZK_TICK_TIME valueFrom:
configMapKeyRef:
name: zk-config key: tick - name : ZK_INIT_LIMIT valueFrom:
configMapKeyRef:
name: zk-config key: init - name : ZK_SYNC_LIMIT valueFrom:
configMapKeyRef:
name: zk-config key: tick - name : ZK_MAX_CLIENT_CNXNS valueFrom:
configMapKeyRef:
name: zk-config key: client.cnxns - name: ZK_SNAP_RETAIN_COUNT valueFrom:
configMapKeyRef:
name: zk-config key: snap.retain - name: ZK_PURGE_INTERVAL valueFrom:
configMapKeyRef:
name: zk-config key: purge.interval - name: ZK_CLIENT_PORT value: "2181"
- name: ZK_SERVER_PORT value: "2888"
- name: ZK_ELECTION_PORT value: "3888"
command:
- sh - -c - && start-foreground readinessProbe:
exec:
command:
- ""
initialDelaySeconds: 15
timeoutSeconds: 5
livenessProbe:
exec:
command:
- ""
initialDelaySeconds: 15
timeoutSeconds: 5
volumeMounts:
- name: data mountPath: /var/lib/zookeeper volumes:
- name: data emptyDir: {}
securityContext:
runAsUser: 1000
fsGroup: 1000# volumeClaimTemplates:# - metadata:# name: data# spec:# accessModes: [ "ReadWriteOnce" ]# storageClassName: "gluster-heketi-2"# resources:# requests:# storage: 2Gi- PodDisruptionBudget：
k8s可以为每个应用程序创建 PodDisruptionBudget 对象（PDB）。PDB 将限制在同一时间因自愿干扰导致的复制应用程序中宕机的 pod 数量。
可以通过两个参数来配置PodDisruptionBudget：
MinAvailable：表示最小可用POD数，表示应用POD集群处于运行状态的最小POD数量，或者是运行状态的POD数同总POD数的最小百分比 MaxUnavailable：表示最大不可用PO数，表示应用POD集群处于不可用状态的最大POD数，或者是不可用状态的POD数同总POD数的最大百分比
需要注意的是，MinAvailable参数和MaxUnavailable参数只能同时配置一个。
- 部署：
kubectl apply -f zookeeper-headless.yaml kubectl get svc NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 25d zk-cs ClusterIP 10.107.243.77 <none> 2181/TCP 29s zk-hs ClusterIP None <none> 2888/TCP,3888/TCP 29s kubectl get pod NAME READY STATUS RESTARTS AGE zk-0 1/1 Running 0 92s zk-1 1/1 Running 0 73s zk-2 1/1 Running 0 48s
- 查看zookeeper配置：
kubectl exec zk-0 cat /opt/zookeeper/conf/zoo.cfg#This file was autogenerated by k8szk DO NOT EDITclientPort=2181 dataDir=/var/lib/zookeeper/data dataLogDir=/var/lib/zookeeper/log tickTime=2000 initLimit=10 syncLimit=2000 maxClientCnxns=60 minSessionTimeout= 4000 maxSessionTimeout= 40000 autopurge.snapRetainCount=3 autopurge.purgeInteval=1 server.1=zk-0.zk-hs.default.svc.cluster.local:2888:3888 server.2=zk-1.zk-hs.default.svc.cluster.local:2888:3888 server.3=zk-2.zk-hs.default.svc.cluster.local:2888:3888
- 查看集群状态：
kubectl exec zk-0 status ZooKeeper JMX enabled by default Using config: /usr/bin/../etc/zookeeper/zoo.cfg Mode: follower kubectl exec zk-1 status ZooKeeper JMX enabled by default Using config: /usr/bin/../etc/zookeeper/zoo.cfg Mode: leader kubectl exec zk-2 status ZooKeeper JMX enabled by default Using config: /usr/bin/../etc/zookeeper/zoo.cfg Mode: follower
可以看到：zk-1 是集群leader，zk-0 和 zk-2 是集群follower。
kubectl exec zk-0 cat /var/lib/zookeeper/data/myid 1 kubectl exec zk-1 cat /var/lib/zookeeper/data/myid 2 kubectl exec zk-2 cat /var/lib/zookeeper/data/myid 3
- 集群测试：
kubectl exec zk-0 create /hello world WATCHER:: WatchedEvent state:SyncConnected type:None path:null Created /hello kubectl exec zk-1 get /hello WATCHER:: WatchedEvent state:SyncConnected type:None path:null cZxid = 0x100000002 world ctime = Sat Jun 06 07:11:23 UTC 2020 mZxid = 0x100000002 mtime = Sat Jun 06 07:11:23 UTC 2020 pZxid = 0x100000002 cversion = 0 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 5 numChildren = 0 kubectl exec zk-2 get /hello WATCHER:: WatchedEvent state:SyncConnected type:None path:null world cZxid = 0x100000002 ctime = Sat Jun 06 07:11:23 UTC 2020 mZxid = 0x100000002 mtime = Sat Jun 06 07:11:23 UTC 2020 pZxid = 0x100000002 cversion = 0 dataVersion = 0 aclVersion = 0 ephemeralOwner = 0x0 dataLength = 5 numChildren = 0
在 zk-0 创建的数据在集群中所有的服务上都是可用的。
参考：
