Question

我在OpenShift / Kubernetes环境中运行Zookeeper。我已将zookeeper设置为@ViewChild("menuSidenav") sideNave: any;，以便可靠地保留配置数据。

我通过主机名在我的this.sideNave.open();中配置了三台服务器，但在启动时，主机名解析失败。我验证了主机名确实可以在我的集群中使用nslookup解析。

zoo.cfg：

StatefulSet

我的OpenShift / Kubernetes配置的相关部分：

zoo.cfg

OpenShift日志显示clientPort=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=0 server.1=zookeeper-0.zookeeper-headless:2888:3888 server.2=zookeeper-1.zookeeper-headless:2888:3888 server.3=zookeeper-2.zookeeper-headless:2888:3888，但是：

  # StatefulSet
  - apiVersion: apps/v1beta1
    kind: StatefulSet
    metadata:
      labels:
        app: zookeeper
      name: zookeeper
    spec:
      serviceName: zookeeper-headless
      replicas: 3
      template:
        metadata:
          labels:
            app: zookeeper
        spec:
          containers:
            - image: 172.30.158.156:5000/os-cloud-platform/zookeeper:latest
              name: zookeeper
              ports:
                - containerPort: 2181
                  protocol: TCP
                  name: client
                - containerPort: 2888
                  protocol: TCP
                  name: server
                - containerPort: 3888
                  protocol: TCP
                  name: leader-election
          dnsPolicy: ClusterFirst
          schedulerName: default-scheduler

  # Service
  - apiVersion: v1
    kind: Service
    metadata:
      labels:
        app: zookeeper
      name: zookeeper
    spec:
      ports:
        - name: client
          port: 2181
          protocol: TCP
          targetPort: 2181
      selector:
        app: zookeeper
      sessionAffinity: None
      type: ClusterIP

  - apiVersion: v1
    kind: Service
    metadata:
      name: zookeeper-headless
      labels:
        app: zookeeper
    spec:
      ports:
        - port: 2888
          name: server
        - port: 3888
          name: leader-election
      clusterIP: None
      selector:
        app: zookeeper

可能是什么原因？我确认主机名（例如UnknownHostException）可通过2017-10-06 10:59:18,289 [myid:] - WARN [main:QuorumPeer$QuorumServer@155] - Failed to resolve address: zookeeper-2.zookeeper-headless java.net.UnknownHostException: zookeeper-2.zookeeper-headless: No address associated with hostname at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method) at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:928) at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1323) at java.net.InetAddress.getAllByName0(InetAddress.java:1276) at java.net.InetAddress.getAllByName(InetAddress.java:1192) at java.net.InetAddress.getAllByName(InetAddress.java:1126) at java.net.InetAddress.getByName(InetAddress.java:1076) at org.apache.zookeeper.server.quorum.QuorumPeer$QuorumServer.recreateSocketAddresses(QuorumPeer.java:148) at org.apache.zookeeper.server.quorum.QuorumPeer$QuorumServer.<init>(QuorumPeer.java:133) at org.apache.zookeeper.server.quorum.QuorumPeerConfig.parseProperties(QuorumPeerConfig.java:228) at org.apache.zookeeper.server.quorum.QuorumPeerConfig.parse(QuorumPeerConfig.java:140) at org.apache.zookeeper.server.quorum.QuorumPeerMain.initializeAndRun(QuorumPeerMain.java:101) at org.apache.zookeeper.server.quorum.QuorumPeerMain.main(QuorumPeerMain.java:78) ...从其他广告连播中获得。

Answer 1

我找到了解决此问题的有效方案。 ZooKeeper在启动时读取集合中的服务器列表，并查找其“自己的”条目。然后，它使用此条目来确定要侦听的端口和接口。

server.1=zookeeper-0.zookeeper-headless:2888:3888
server.2=zookeeper-1.zookeeper-headless:2888:3888
server.3=zookeeper-2.zookeeper-headless:2888:3888

由于提供的主机名将在此计算机上解析为127.0.0.1，因此ZooKeeper将侦听本地环回接口，因此不接受来自其他ZooKeeper服务器的连接。

server.1=0.0.0.0:2888:3888
server.2=zookeeper-1.zookeeper-headless:2888:3888
server.3=zookeeper-2.zookeeper-headless:2888:3888

为了自动化集群中的东西，我编写了一个bash脚本，它将替换容器启动时的一个“自己的”条目。

编辑：正如评论中所述，这是我的ENTRYPOINT脚本，负责放置myid文件并为每个zoo.cfg设置适当的主机名：

#!/bin/bash
# This script extracts the number out of the pod's hostname and sets it as zookeepers id.

# Exact paths may vary according to your setup
MYID_FILE="/var/lib/zookeeper/data/myid"
ZOOCFG_FILE="/conf/zoo.cfg"

# Create myid-file
# Extract only numbers from hostname
id=$(hostname | tr -d -c 0-9)
echo $id > "${MYID_FILE}"

# change own hostname to 0.0.0.0
# otherwise, the own hostname will resolve to 127.0.0.1
# https://stackoverflow.com/a/40750900/5764665
fullHostname="$(hostname).zookeeper-headless"
sed -i -e "s/${fullHostname}/0.0.0.0/g" "${ZOOCFG_FILE}"

echo "Executing $@"
exec "$@"

Zookeeper：主机名解析失败

1 个答案: