我正在 kubernetes (Azure AKS( 中设置多节点 cassandra 集群,因为这是一个无头服务,具有有状态的设置 pod,没有外部 IP。如何将我的 Spark 应用程序与 kubernetes 集群中的 cassandra 连接
起来我们已经尝试过使用集群 ip,入口 ip,但只有一个 pod 正在休息失败。
我有 3 个清单:
- 服务
- 持久卷声明
- 有状态集
apiVersion: v1
kind: Service
metadata:
labels:
app: cassandra
name: cassandra
spec:
clusterIP: None
ports:
- port: 9042
selector:
app: cassandra
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: myvolume-disk-claim
spec:
storageClassName: default
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 10Gi
apiVersion: "apps/v1"
kind: StatefulSet
metadata:
name: cassandra
labels:
app: cassandra
spec:
serviceName: cassandra
replicas: 3
selector:
matchLabels:
app: cassandra
template:
metadata:
labels:
app: cassandra
spec:
containers:
- name: cassandra
image: gcr.io/google-samples/cassandra:v13
imagePullPolicy: Always
ports:
- containerPort: 7000
name: intra-node
- containerPort: 7001
name: tls-intra-node
- containerPort: 7199
name: jmx
- containerPort: 9042
name: cql
env:
- name: CASSANDRA_SEEDS
value: cassandra-0.cassandra.default.svc.cluster.local
- name: MAX_HEAP_SIZE
value: 256M
- name: HEAP_NEWSIZE
value: 100M
- name: CASSANDRA_CLUSTER_NAME
value: "Cassandra"
- name: CASSANDRA_DC
value: "DC1"
- name: CASSANDRA_RACK
value: "Rack1"
- name: CASSANDRA_ENDPOINT_SNITCH
value: GossipingPropertyFileSnitch
- name: POD_IP
valueFrom:
fieldRef:
fieldPath: status.podIP
readinessProbe:
exec:
command:
- /bin/bash
- -c
- /ready-probe.sh
initialDelaySeconds: 15
timeoutSeconds: 5
volumeMounts:
- mountPath: /var/lib/cassandra/data
name: myvolume-disk-claim
volumeClaimTemplates:
- metadata:
name: myvolume-disk-claim
spec:
storageClassName: default
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 10Gi
预期成果:(公共IP作为外部IP(
dspg@Digiteds28:$ kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.0.0.1 <none> 443/TCP 1h
cassandra ClusterIP None 154.167.90.98 9042/TCP 1h
dspg@Digiteds28:$ kubectl get pod
NAME READY STATUS RESTARTS AGE
cassandra-0 1/1 Running 0 59m
cassandra-1 1/1 Running 0 58m
cassandra-2 1/1 Running 0 56m
实际输出:
dspg@Digiteds28:$ kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.0.0.1 <none> 443/TCP 1h
cassandra ClusterIP None <none> 9042/TCP 1h
dspg@Digiteds28:$ kubectl get pod
NAME READY STATUS RESTARTS AGE
cassandra-0 1/1 Running 0 59m
cassandra-1 1/1 Running 0 58m
cassandra-2 1/1 Running 0 56m
现在,这不包括用于连接到应用程序的外部 IP。
这取决于你到底想做什么。如果您需要外部IP,那么通常您需要创建一个额外的服务对象(可能是type: LoadBalancer
(,如下所示:
apiVersion: v1
kind: Service
metadata:
labels:
app: cassandra
name: cassandra-ext
spec:
type: LoadBalancer
ports:
- port: 9042
selector:
app: cassandra
如果需要从群集内访问它,请使用其他 Pod 中cassandra-0.cassandra.default
的 DNS 名称(如果 StatefulSet 部署在默认命名空间中(
apiVersion: v1
kind: Service
metadata:
labels:
app: cassandra
name: cassandra-ext
spec:
type: LoadBalancer
ports:
- port: 9042
selector:
app: cassandra
使用附加服务给了我一个外部IP,因为如果它我开始将我的Spark或devcenter应用程序连接到Cassandra集群。