I. Resumen
Antes de Hadoop 2.0.0, un clúster tenía solo un Namenode, que enfrentaría el problema del punto único de falla. Si la máquina Namenode muere, todo el clúster se vuelve inútil. El clúster solo se puede recuperar reiniciando Namenode. Además, cuando normalmente se planea mantener el clúster, primero se debe desactivar todo el clúster, por lo que no hay forma de lograr un estado de disponibilidad de 7 * 24 horas. Hadoop 2.0 y versiones posteriores agregaron el mecanismo de alta disponibilidad de Namenode Aquí hablamos principalmente sobre la implementación de Hadoop HA en el entorno k8s.
Para entornos k8s que no sean de alta disponibilidad, consulte mi artículo: [Cloud native] Hadoop en la implementación del entorno k8s
Para entornos que no sean k8s de alta disponibilidad, consulte mi artículo: Big Data Hadoop: Hadoop 3.3.4 HA (alta disponibilidad) Principio e Implementación (QJM)
HILO HDFS
2. Iniciar la implementación
Aquí hay una transformación basada en una orquestación que no es de alta disponibilidad. Para aquellos que no saben, pueden leer mi artículo anterior.
1) Agregar orquestación journalNode
1. Conjunto de estado del controlador
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: {{ include "hadoop.fullname" . }}-hdfs-jn
annotations:
checksum/config: {{ include (print $.Template.BasePath "/hadoop-configmap.yaml") . | sha256sum }}
labels:
app.kubernetes.io/name: {{ include "hadoop.name" . }}
helm.sh/chart: {{ include "hadoop.chart" . }}
app.kubernetes.io/instance: {{ .Release.Name }}
app.kubernetes.io/component: hdfs-jn
spec:
selector:
matchLabels:
app.kubernetes.io/name: {{ include "hadoop.name" . }}
app.kubernetes.io/instance: {{ .Release.Name }}
app.kubernetes.io/component: hdfs-jn
serviceName: {{ include "hadoop.fullname" . }}-hdfs-jn
replicas: {{ .Values.hdfs.jounralNode.replicas }}
template:
metadata:
labels:
app.kubernetes.io/name: {{ include "hadoop.name" . }}
app.kubernetes.io/instance: {{ .Release.Name }}
app.kubernetes.io/component: hdfs-jn
spec:
affinity:
podAntiAffinity:
{{- if eq .Values.antiAffinity "hard" }}
requiredDuringSchedulingIgnoredDuringExecution:
- topologyKey: "kubernetes.io/hostname"
labelSelector:
matchLabels:
app.kubernetes.io/name: {{ include "hadoop.name" . }}
app.kubernetes.io/instance: {{ .Release.Name }}
app.kubernetes.io/component: hdfs-jn
{{- else if eq .Values.antiAffinity "soft" }}
preferredDuringSchedulingIgnoredDuringExecution:
- weight: 5
podAffinityTerm:
topologyKey: "kubernetes.io/hostname"
labelSelector:
matchLabels:
app.kubernetes.io/name: {{ include "hadoop.name" . }}
app.kubernetes.io/instance: {{ .Release.Name }}
app.kubernetes.io/component: hdfs-jn
{{- end }}
terminationGracePeriodSeconds: 0
containers:
- name: hdfs-jn
image: "{{ .Values.image.repository }}:{{ .Values.image.tag }}"
imagePullPolicy: {{ .Values.image.pullPolicy | quote }}
command:
- "/bin/bash"
- "/opt/apache/tmp/hadoop-config/bootstrap.sh"
- "-d"
resources:
{{ toYaml .Values.hdfs.jounralNode.resources | indent 10 }}
readinessProbe:
tcpSocket:
port: 8485
initialDelaySeconds: 10
timeoutSeconds: 2
livenessProbe:
tcpSocket:
port: 8485
initialDelaySeconds: 10
timeoutSeconds: 2
volumeMounts:
- name: hadoop-config
mountPath: /opt/apache/tmp/hadoop-config
{{- range .Values.persistence.journalNode.volumes }}
- name: {{ .name }}
mountPath: {{ .mountPath }}
{{- end }}
securityContext:
runAsUser: {{ .Values.securityContext.runAsUser }}
privileged: {{ .Values.securityContext.privileged }}
volumes:
- name: hadoop-config
configMap:
name: {{ include "hadoop.fullname" . }}
{{- if .Values.persistence.journalNode.enabled }}
volumeClaimTemplates:
{{- range .Values.persistence.journalNode.volumes }}
- metadata:
name: {{ .name }}
labels:
app.kubernetes.io/name: {{ include "hadoop.name" $ }}
helm.sh/chart: {{ include "hadoop.chart" $ }}
app.kubernetes.io/instance: {{ $.Release.Name }}
app.kubernetes.io/component: hdfs-jn
spec:
accessModes:
- {{ $.Values.persistence.journalNode.accessMode | quote }}
resources:
requests:
storage: {{ $.Values.persistence.journalNode.size | quote }}
{{- if $.Values.persistence.journalNode.storageClass }}
{{- if (eq "-" $.Values.persistence.journalNode.storageClass) }}
storageClassName: ""
{{- else }}
storageClassName: "{{ $.Values.persistence.journalNode.storageClass }}"
{{- end }}
{{- end }}
{{- else }}
- name: dfs
emptyDir: {}
{{- end }}
{{- end }}
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2, servicio
# A headless service to create DNS records
apiVersion: v1
kind: Service
metadata:
name: {{ include "hadoop.fullname" . }}-hdfs-jn
labels:
app.kubernetes.io/name: {{ include "hadoop.name" . }}
helm.sh/chart: {{ include "hadoop.chart" . }}
app.kubernetes.io/instance: {{ .Release.Name }}
app.kubernetes.io/component: hdfs-jn
spec:
ports:
- name: jn
port: {{ .Values.service.journalNode.ports.jn }}
protocol: TCP
{{- if and (eq .Values.service.journalNode.type "NodePort") .Values.service.journalNode.nodePorts.jn }}
nodePort: {{ .Values.service.journalNode.nodePorts.jn }}
{{- end }}
type: {{ .Values.service.journalNode.type }}
selector:
app.kubernetes.io/name: {{ include "hadoop.name" . }}
app.kubernetes.io/instance: {{ .Release.Name }}
app.kubernetes.io/component: hdfs-jn
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2) Modificar la configuración
1. Modificar valores.yaml
image:
repository: myharbor.com/bigdata/hadoop
tag: 3.3.2
pullPolicy: IfNotPresent
# The version of the hadoop libraries being used in the image.
hadoopVersion: 3.3.2
logLevel: INFO
# Select antiAffinity as either hard or soft, default is soft
antiAffinity: "soft"
hdfs:
nameNode:
replicas: 2
pdbMinAvailable: 1
resources:
requests:
memory: "256Mi"
cpu: "10m"
limits:
memory: "2048Mi"
cpu: "1000m"
dataNode:
# Will be used as dfs.datanode.hostname
# You still need to set up services + ingress for every DN
# Datanodes will expect to
externalHostname: example.com
externalDataPortRangeStart: 9866
externalHTTPPortRangeStart: 9864
replicas: 3
pdbMinAvailable: 1
resources:
requests:
memory: "256Mi"
cpu: "10m"
limits:
memory: "2048Mi"
cpu: "1000m"
webhdfs:
enabled: true
jounralNode:
replicas: 3
pdbMinAvailable: 1
resources:
requests:
memory: "256Mi"
cpu: "10m"
limits:
memory: "2048Mi"
cpu: "1000m"
yarn:
resourceManager:
pdbMinAvailable: 1
replicas: 2
resources:
requests:
memory: "256Mi"
cpu: "10m"
limits:
memory: "2048Mi"
cpu: "2000m"
nodeManager:
pdbMinAvailable: 1
# The number of YARN NodeManager instances.
replicas: 1
# Create statefulsets in parallel (K8S 1.7+)
parallelCreate: false
# CPU and memory resources allocated to each node manager pod.
# This should be tuned to fit your workload.
resources:
requests:
memory: "256Mi"
cpu: "500m"
limits:
memory: "2048Mi"
cpu: "1000m"
persistence:
nameNode:
enabled: true
storageClass: "hadoop-ha-nn-local-storage"
accessMode: ReadWriteOnce
size: 1Gi
local:
- name: hadoop-ha-nn-0
host: "local-168-182-110"
path: "/opt/bigdata/servers/hadoop-ha/nn/data/data1"
- name: hadoop-ha-nn-1
host: "local-168-182-111"
path: "/opt/bigdata/servers/hadoop-ha/nn/data/data1"
dataNode:
enabled: true
enabledStorageClass: false
storageClass: "hadoop-ha-dn-local-storage"
accessMode: ReadWriteOnce
size: 1Gi
local:
- name: hadoop-ha-dn-0
host: "local-168-182-110"
path: "/opt/bigdata/servers/hadoop-ha/dn/data/data1"
- name: hadoop-ha-dn-1
host: "local-168-182-110"
path: "/opt/bigdata/servers/hadoop-ha/dn/data/data2"
- name: hadoop-ha-dn-2
host: "local-168-182-110"
path: "/opt/bigdata/servers/hadoop-ha/dn/data/data3"
- name: hadoop-ha-dn-3
host: "local-168-182-111"
path: "/opt/bigdata/servers/hadoop-ha/dn/data/data1"
- name: hadoop-ha-dn-4
host: "local-168-182-111"
path: "/opt/bigdata/servers/hadoop-ha/dn/data/data2"
- name: hadoop-ha-dn-5
host: "local-168-182-111"
path: "/opt/bigdata/servers/hadoop-ha/dn/data/data3"
- name: hadoop-ha-dn-6
host: "local-168-182-112"
path: "/opt/bigdata/servers/hadoop-ha/dn/data/data1"
- name: hadoop-ha-dn-7
host: "local-168-182-112"
path: "/opt/bigdata/servers/hadoop-ha/dn/data/data2"
- name: hadoop-ha-dn-8
host: "local-168-182-112"
path: "/opt/bigdata/servers/hadoop-ha/dn/data/data3"
volumes:
- name: dfs1
mountPath: /opt/apache/hdfs/datanode1
hostPath: /opt/bigdata/servers/hadoop-ha/dn/data/data1
- name: dfs2
mountPath: /opt/apache/hdfs/datanode2
hostPath: /opt/bigdata/servers/hadoop-ha/dn/data/data2
- name: dfs3
mountPath: /opt/apache/hdfs/datanode3
hostPath: /opt/bigdata/servers/hadoop-ha/dn/data/data3
journalNode:
enabled: true
storageClass: "hadoop-ha-jn-local-storage"
accessMode: ReadWriteOnce
size: 1Gi
local:
- name: hadoop-ha-jn-0
host: "local-168-182-110"
path: "/opt/bigdata/servers/hadoop-ha/jn/data/data1"
- name: hadoop-ha-jn-1
host: "local-168-182-111"
path: "/opt/bigdata/servers/hadoop-ha/jn/data/data1"
- name: hadoop-ha-jn-2
host: "local-168-182-112"
path: "/opt/bigdata/servers/hadoop-ha/jn/data/data1"
volumes:
- name: jn
mountPath: /opt/apache/hdfs/journalnode
service:
nameNode:
type: NodePort
ports:
dfs: 9000
webhdfs: 9870
nodePorts:
dfs: 30900
webhdfs: 30870
dataNode:
type: NodePort
ports:
webhdfs: 9864
nodePorts:
webhdfs: 30864
resourceManager:
type: NodePort
ports:
web: 8088
nodePorts:
web: 30088
journalNode:
type: ClusterIP
ports:
jn: 8485
nodePorts:
jn: ""
securityContext:
runAsUser: 9999
privileged: true
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2. Modificar hadoop/templates/hadoop-configmap.yaml
Hay mucho contenido modificado, por lo que no lo publicaré aquí. La dirección de descarga de git se proporcionará en la parte inferior.
3) Iniciar la instalación
# 创建存储目录
mkdir -p /opt/bigdata/servers/hadoop-ha/{nn,dn,jn}/data/data{1..3}
chmod -R 777 -R /opt/bigdata/servers/hadoop-ha/{nn,dn,jn}
helm install hadoop-ha ./hadoop -n hadoop-ha --create-namespace
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Controlar
kubectl get pods,svc -n hadoop-ha -owide
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HDFS WEB-nn1: http://192.168.182.110:31870/dfshealth.html#tab-overview
HDFS WEB-nn2: http://192.168.182.110:31871/dfshealth.html#tab-overview YARN WEB-rm1: http://192.168.182.110:31088/cluster/cluster YARN WEB-rm2: http://192.168 .182.110:31089/clúster/clúster
4) Verificación de prueba
kubectl exec -it hadoop-ha-hadoop-hdfs-nn-0 -n hadoop-ha -- bash
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5) Desinstalar
helm uninstall hadoop-ha -n hadoop-ha
kubectl delete pod -n hadoop-ha `kubectl get pod -n hadoop-ha|awk 'NR>1{print $1}'` --force
kubectl patch ns hadoop-ha -p '{"metadata":{"finalizers":null}}'
kubectl delete ns hadoop-ha --force
rm -fr /opt/bigdata/servers/hadoop-ha/{nn,dn,jn}/data/data{1..3}/*
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dirección de descarga de git: gitee.com/hadoop-bigd…
Hadoop HA en la implementación del entorno k8s está aquí primero. No hay muchas descripciones aquí. Si tiene alguna pregunta, déjeme un mensaje. Puede haber algunas áreas que no sean perfectas. Continuaremos mejorando y agregando otros servicios en esta base Continúe compartiendo artículos relacionados con [big data + cloud native], espere pacientemente ~