k8s部署flink session高可用集群

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1.flink高可用部署模式

  • Application 集群模式

  • Per-Job 集群模式,在 Kubernetes 上部署 Standalone 集群时不支持 Per-Job 集群模式。

  • Session 集群模式 2.启用集群高可用

  • 依赖ZooKeeper的高可用服务

  • 依赖Kubernetes 高可用服务 3.环境准备,为了使用 Flink 的 Kubernetes 高可用服务,你必须满足以下先决条件:

  • Kubernetes >= 1.9.

  • 具有创建、编辑、删除 ConfigMaps 权限的服务帐户。想了解更多信息,请查看如何在 Flink 原生 Kubernetes 集成 和 在 Kubernetes 上单节点部署 Flink 两种模式中配置服务帐户。

  • flink的Dockerfile

FROM flink:1.13.5-scala_2.11

ADD ./flink-conf.yaml /opt/flink/conf/flink-conf.yaml
# 在容器中创建目录
RUN mkdir -p /opt/flink/flink-web-upload
  • flink的配置文件
################################################################################
#  Licensed to the Apache Software Foundation (ASF) under one
#  or more contributor license agreements.  See the NOTICE file
#  distributed with this work for additional information
#  regarding copyright ownership.  The ASF licenses this file
#  to you under the Apache License, Version 2.0 (the
#  "License"); you may not use this file except in compliance
#  with the License.  You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
# limitations under the License.
################################################################################


#==============================================================================
# Common
#==============================================================================

# The external address of the host on which the JobManager runs and can be
# reached by the TaskManagers and any clients which want to connect. This setting
# is only used in Standalone mode and may be overwritten on the JobManager side
# by specifying the --host <hostname> parameter of the bin/jobmanager.sh executable.
# In high availability mode, if you use the bin/start-cluster.sh script and setup
# the conf/masters file, this will be taken care of automatically. Yarn
# automatically configure the host name based on the hostname of the node where the
# JobManager runs.

jobmanager.rpc.address: localhost

# The RPC port where the JobManager is reachable.

#指定jar上传路径
web.upload.dir: /opt/flink
jobmanager.rpc.port: 6123


# The total process memory size for the JobManager.
#
# Note this accounts for all memory usage within the JobManager process, including JVM metaspace and other overhead.

jobmanager.memory.process.size: 1600m


# The total process memory size for the TaskManager.
#
# Note this accounts for all memory usage within the TaskManager process, including JVM metaspace and other overhead.

taskmanager.memory.process.size: 1728m

# To exclude JVM metaspace and overhead, please, use total Flink memory size instead of 'taskmanager.memory.process.size'.
# It is not recommended to set both 'taskmanager.memory.process.size' and Flink memory.
#
# taskmanager.memory.flink.size: 1280m

# The number of task slots that each TaskManager offers. Each slot runs one parallel pipeline.

taskmanager.numberOfTaskSlots: 1

# The parallelism used for programs that did not specify and other parallelism.

parallelism.default: 1

# The default file system scheme and authority.
# 
# By default file paths without scheme are interpreted relative to the local
# root file system 'file:///'. Use this to override the default and interpret
# relative paths relative to a different file system,
# for example 'hdfs://mynamenode:12345'
#
# fs.default-scheme

#==============================================================================
# High Availability
#==============================================================================

# The high-availability mode. Possible options are 'NONE' or 'zookeeper'.
#
# high-availability: zookeeper

# The path where metadata for master recovery is persisted. While ZooKeeper stores
# the small ground truth for checkpoint and leader election, this location stores
# the larger objects, like persisted dataflow graphs.
# 
# Must be a durable file system that is accessible from all nodes
# (like HDFS, S3, Ceph, nfs, ...) 
#
# high-availability.storageDir: hdfs:///flink/ha/

# The list of ZooKeeper quorum peers that coordinate the high-availability
# setup. This must be a list of the form:
# "host1:clientPort,host2:clientPort,..." (default clientPort: 2181)
#
# high-availability.zookeeper.quorum: localhost:2181


# ACL options are based on https://zookeeper.apache.org/doc/r3.1.2/zookeeperProgrammers.html#sc_BuiltinACLSchemes
# It can be either "creator" (ZOO_CREATE_ALL_ACL) or "open" (ZOO_OPEN_ACL_UNSAFE)
# The default value is "open" and it can be changed to "creator" if ZK security is enabled
#
# high-availability.zookeeper.client.acl: open

#==============================================================================
# Fault tolerance and checkpointing
#==============================================================================

# The backend that will be used to store operator state checkpoints if
# checkpointing is enabled. Checkpointing is enabled when execution.checkpointing.interval > 0.
#
# Execution checkpointing related parameters. Please refer to CheckpointConfig and ExecutionCheckpointingOptions for more details.
#
# execution.checkpointing.interval: 3min
# execution.checkpointing.externalized-checkpoint-retention: [DELETE_ON_CANCELLATION, RETAIN_ON_CANCELLATION]
# execution.checkpointing.max-concurrent-checkpoints: 1
# execution.checkpointing.min-pause: 0
# execution.checkpointing.mode: [EXACTLY_ONCE, AT_LEAST_ONCE]
# execution.checkpointing.timeout: 10min
# execution.checkpointing.tolerable-failed-checkpoints: 0
# execution.checkpointing.unaligned: false
#
# Supported backends are 'jobmanager', 'filesystem', 'rocksdb', or the
# <class-name-of-factory>.
#
# state.backend: filesystem

# Directory for checkpoints filesystem, when using any of the default bundled
# state backends.
#
# state.checkpoints.dir: hdfs://namenode-host:port/flink-checkpoints

# Default target directory for savepoints, optional.
#
# state.savepoints.dir: hdfs://namenode-host:port/flink-savepoints

# Flag to enable/disable incremental checkpoints for backends that
# support incremental checkpoints (like the RocksDB state backend). 
#
# state.backend.incremental: false

# The failover strategy, i.e., how the job computation recovers from task failures.
# Only restart tasks that may have been affected by the task failure, which typically includes
# downstream tasks and potentially upstream tasks if their produced data is no longer available for consumption.

jobmanager.execution.failover-strategy: region

#==============================================================================
# Rest & web frontend
#==============================================================================

# The port to which the REST client connects to. If rest.bind-port has
# not been specified, then the server will bind to this port as well.
#
#rest.port: 8081

# The address to which the REST client will connect to
#
#rest.address: 0.0.0.0

# Port range for the REST and web server to bind to.
#
#rest.bind-port: 8080-8090

# The address that the REST & web server binds to
#
#rest.bind-address: 0.0.0.0

# Flag to specify whether job submission is enabled from the web-based
# runtime monitor. Uncomment to disable.

#web.submit.enable: false

# Flag to specify whether job cancellation is enabled from the web-based
# runtime monitor. Uncomment to disable.

#web.cancel.enable: false

#==============================================================================
# Advanced
#==============================================================================

# Override the directories for temporary files. If not specified, the
# system-specific Java temporary directory (java.io.tmpdir property) is taken.
#
# For framework setups on Yarn, Flink will automatically pick up the
# containers' temp directories without any need for configuration.
#
# Add a delimited list for multiple directories, using the system directory
# delimiter (colon ':' on unix) or a comma, e.g.:
#     /data1/tmp:/data2/tmp:/data3/tmp
#
# Note: Each directory entry is read from and written to by a different I/O
# thread. You can include the same directory multiple times in order to create
# multiple I/O threads against that directory. This is for example relevant for
# high-throughput RAIDs.
#
# io.tmp.dirs: /tmp

# The classloading resolve order. Possible values are 'child-first' (Flink's default)
# and 'parent-first' (Java's default).
#
# Child first classloading allows users to use different dependency/library
# versions in their application than those in the classpath. Switching back
# to 'parent-first' may help with debugging dependency issues.
#
# classloader.resolve-order: child-first

# The amount of memory going to the network stack. These numbers usually need 
# no tuning. Adjusting them may be necessary in case of an "Insufficient number
# of network buffers" error. The default min is 64MB, the default max is 1GB.
# 
# taskmanager.memory.network.fraction: 0.1
# taskmanager.memory.network.min: 64mb
# taskmanager.memory.network.max: 1gb

#==============================================================================
# Flink Cluster Security Configuration
#==============================================================================

# Kerberos authentication for various components - Hadoop, ZooKeeper, and connectors -
# may be enabled in four steps:
# 1. configure the local krb5.conf file
# 2. provide Kerberos credentials (either a keytab or a ticket cache w/ kinit)
# 3. make the credentials available to various JAAS login contexts
# 4. configure the connector to use JAAS/SASL

# The below configure how Kerberos credentials are provided. A keytab will be used instead of
# a ticket cache if the keytab path and principal are set.

# security.kerberos.login.use-ticket-cache: true
# security.kerberos.login.keytab: /path/to/kerberos/keytab
# security.kerberos.login.principal: flink-user

# The configuration below defines which JAAS login contexts

# security.kerberos.login.contexts: Client,KafkaClient

#==============================================================================
# ZK Security Configuration
#==============================================================================

# Below configurations are applicable if ZK ensemble is configured for security

# Override below configuration to provide custom ZK service name if configured
# zookeeper.sasl.service-name: zookeeper

# The configuration below must match one of the values set in "security.kerberos.login.contexts"
# zookeeper.sasl.login-context-name: Client

#==============================================================================
# HistoryServer
#==============================================================================

# The HistoryServer is started and stopped via bin/historyserver.sh (start|stop)

# Directory to upload completed jobs to. Add this directory to the list of
# monitored directories of the HistoryServer as well (see below).
#jobmanager.archive.fs.dir: hdfs:///completed-jobs/

# The address under which the web-based HistoryServer listens.
#historyserver.web.address: 0.0.0.0

# The port under which the web-based HistoryServer listens.
#historyserver.web.port: 8082

# Comma separated list of directories to monitor for completed jobs.
#historyserver.archive.fs.dir: hdfs:///completed-jobs/

# Interval in milliseconds for refreshing the monitored directories.
#historyserver.archive.fs.refresh-interval: 10000
注: 
1.本教程依赖Kubernetes 高可用服务
2.k8s服务帐户会在后面给出yaml文件

3.部署yaml文件

  • deployments
apiVersion: apps/v1
kind: Deployment
metadata:
  name: flink-jobmanager
  namespace: transport-ns-dev    
spec:
  replicas: 2 # 通过设置大于 1 的整型值来开启 Standby JobManager
  selector:
    matchLabels:
      app: flink
      component: jobmanager
  template:
    metadata:
      labels:
        app: flink
        component: jobmanager
    spec:
      containers:
      - name: jobmanager
        image: flink:1
        env:
        - name: POD_IP
          valueFrom:
            fieldRef:
              apiVersion: v1
              fieldPath: status.podIP
        # 下面的 args 参数会使用 POD_IP 对应的值覆盖 config map 中 jobmanager.rpc.address 的属性值。
        args: ["jobmanager", "$(POD_IP)"]
        ports:
        - containerPort: 6123
          name: rpc
        - containerPort: 6124
          name: blob-server
        - containerPort: 8081
          name: webui

        volumeMounts:
        - name: flink-config-volume
          mountPath: /opt/flink/conf
        - name: flink-jar
          mountPath: /opt/flink/flink-web-upload  
        securityContext:
          runAsUser: 9999  # 参考官方 flink 镜像中的 _flink_ 用户,如有必要可以修改
      serviceAccountName: flink-service-account # 拥有创建、编辑、删除 ConfigMap 权限的 Service 账号
      volumes:
      - name: flink-config-volume
        configMap:
          name: flink-config
          items:
          - key: flink-conf.yaml
            path: flink-conf.yaml
          - key: log4j-console.properties
            path: log4j-console.properties
      - name: flink-jar      
        persistentVolumeClaim:
          claimName: flink-jar-pvc  
        livenessProbe:
          tcpSocket:
            port: 6123
          initialDelaySeconds: 30
          periodSeconds: 60
        readinessProbe:
          tcpSocket:
            port: 6123
          initialDelaySeconds: 110
          imagePullPolicy: Always
      restartPolicy: Always
      imagePullSecrets:
        - name: jp-nexus-secret

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: flink-taskmanager
  namespace: transport-ns-dev    

spec:
  replicas: 3
  selector:
    matchLabels:
      app: flink
      component: taskmanager
  template:
    metadata:
      labels:
        app: flink
        component: taskmanager
    spec:
      containers:
      - name: taskmanager
        image: flink:1
        args: ["taskmanager"]
        ports:
        - containerPort: 6122
          name: rpc
        - containerPort: 6125
          name: query-state
        volumeMounts:
        - name: flink-config-volume
          mountPath: /opt/flink/conf/
        securityContext:
          runAsUser: 9999  # 参考官方 flink 镜像中的 _flink_ 用户,如有必要可以修改
      volumes:
      - name: flink-config-volume
        configMap:
          name: flink-config
          items:
          - key: flink-conf.yaml
            path: flink-conf.yaml
          - key: log4j-console.properties
            path: log4j-console.properties
        livenessProbe:
          tcpSocket:
            port: 6122
          initialDelaySeconds: 30
          periodSeconds: 60
        readinessProbe:
          tcpSocket:
            port: 6122
          initialDelaySeconds: 110
          imagePullPolicy: Always
      restartPolicy: Always
      imagePullSecrets:
        - name: jp-nexus-secret     

注:

1.这里在yaml文件中配置了serviceCount账号
2.当启用了高可用,Flink 会使用自己的 HA 服务进行服务发现。因此,JobManager Pod 会使用 IP 地址而不是 Kubernetes 的 service 名称来作为 `jobmanager.rpc.address` 的配置项启动。
  • Config Maps
apiVersion: v1
kind: ConfigMap
metadata:
  name: flink-config
  namespace: transport-ns-dev  
  labels:
    app: flink
data:
  flink-conf.yaml: |+
    jobmanager.rpc.address: flink-jobmanager
    taskmanager.numberOfTaskSlots: 2
    blob.server.port: 6124
    jobmanager.rpc.port: 6123
    taskmanager.rpc.port: 6122
    queryable-state.proxy.ports: 6125
    jobmanager.memory.process.size: 1600m
    taskmanager.memory.process.size: 1728m
    web.upload.dir: /opt/flink
    parallelism.default: 2  
    kubernetes.cluster-id: flink-ha
    high-availability: org.apache.flink.kubernetes.highavailability.KubernetesHaServicesFactory
    high-availability.storageDir: file:/flink/recovery  #存储数据到本地文件系统
    restart-strategy: fixed-delay
    restart-strategy.fixed-delay.attempts: 10
  log4j-console.properties: |+
    # 如下配置会同时影响用户代码和 Flink 的日志行为
    rootLogger.level = INFO
    rootLogger.appenderRef.console.ref = ConsoleAppender
    rootLogger.appenderRef.rolling.ref = RollingFileAppender

    # 如果你只想改变 Flink 的日志行为则可以取消如下的注释部分
    #logger.flink.name = org.apache.flink
    #logger.flink.level = INFO

    # 下面几行将公共 libraries 或 connectors 的日志级别保持在 INFO 级别。
    # root logger 的配置不会覆盖此处配置。
    # 你必须手动修改这里的日志级别。
    logger.akka.name = akka
    logger.akka.level = INFO
    logger.kafka.name= org.apache.kafka
    logger.kafka.level = INFO
    logger.hadoop.name = org.apache.hadoop
    logger.hadoop.level = INFO
    logger.zookeeper.name = org.apache.zookeeper
    logger.zookeeper.level = INFO

    # 将所有 info 级别的日志输出到 console
    appender.console.name = ConsoleAppender
    appender.console.type = CONSOLE
    appender.console.layout.type = PatternLayout
    appender.console.layout.pattern = %d{yyyy-MM-dd HH:mm:ss,SSS} %-5p %-60c %x - %m%n

    # 将所有 info 级别的日志输出到指定的 rolling file
    appender.rolling.name = RollingFileAppender
    appender.rolling.type = RollingFile
    appender.rolling.append = false
    appender.rolling.fileName = ${sys:log.file}
    appender.rolling.filePattern = ${sys:log.file}.%i
    appender.rolling.layout.type = PatternLayout
    appender.rolling.layout.pattern = %d{yyyy-MM-dd HH:mm:ss,SSS} %-5p %-60c %x - %m%n
    appender.rolling.policies.type = Policies
    appender.rolling.policies.size.type = SizeBasedTriggeringPolicy
    appender.rolling.policies.size.size=100MB
    appender.rolling.strategy.type = DefaultRolloverStrategy
    appender.rolling.strategy.max = 10

    # 关闭 Netty channel handler 中不相关的(错误)警告
    logger.netty.name = org.jboss.netty.channel.DefaultChannelPipeline
    logger.netty.level = OFF              

注意事项:

  • web.upload.dir: /opt/flink是flink镜像存放jar目录,是我自己构建镜像是创建的
  • high-availability.storageDir: file:/flink/recovery,这个配置我使用的是本地文件,在flink使用本地文件系统

文件系统介绍:nightlies.apache.org/flink/flink…

  • service
###可选的 service,该 service 将 jobmanager 的 `rest` 端口暴露为公共 Kubernetes node 的节点端口。

apiVersion: v1
kind: Service
metadata:
  name: flink-jobmanager-rest
  namespace: transport-ns-dev  
spec:
  type: NodePort
  ports:
  - name: rest
    port: 8081
    targetPort: 8081
    nodePort: 30082
  selector:
    app: flink
    component: jobmanager
---
###该service将TaskManager的端口暴露为公共 Kubernetes node 的节点端口,通过该端口来访问 queryable state 服务。

apiVersion: v1
kind: Service
metadata:
  name: flink-taskmanager-query-state
  namespace: transport-ns-dev  
spec:
  type: NodePort
  ports:
  - name: query-state
    port: 6125
    targetPort: 6125
    nodePort: 30025
  selector:
    app: flink
    component: taskmanager    
  • ServiceAccount
apiVersion: v1
kind: ServiceAccount
metadata:
  name: flink-service-account  
  namespace: transport-ns-dev  
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  namespace: transport-ns-dev
  name: configmap-updater
rules:
- apiGroups: [""]
  resources: ["configmaps"]
  verbs: ["update", "get","create","delete","watch","list"]
---
###一开始绑定了这个用户权限,发现后台任然报错403,就使用了ClusterRoleBinding,即集群最高权限
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: flink-pods
  namespace: transport-ns-dev
subjects:
- kind: ServiceAccount
  name: flink-service-account
  namespace: transport-ns-dev
roleRef:
  kind: Role 
  name: configmap-updater     
  apiGroup: rbac.authorization.k8s.io

---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: flink-pods-cluster-role 
subjects:
  - kind: ServiceAccount
    name: flink-service-account
    namespace: transport-ns-dev
roleRef:
  kind: ClusterRole 
  name: cluster-admin #k8s集群中最高权限的角色
  apiGroup: rbac.authorization.k8s.io
  
  • PersistentVolumeClaim
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: flink-jar-pvc
  namespace: transport-ns-dev
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 5Gi
  storageClassName: traffic-nfs-storage
  volumeMode: Filesystem

注: 持久化实时任务jar,因为k8s节点会漂移,所以需要将实时任务jar持久化