kafka-server-start.sh启动报错：WARN Session 0x0 for server localhost_eventthread shut down for session: 0x0

kafka-server-start.sh启动报错：WARN Session 0x0 for server localhost/<unresolved>:2181
学习来源：百度 CSDN
学习程度：了解 1 
    前言：之前用SpringBoot-2.2.5  和kafka-2.5.0（后端），kafka-2.5.0（服务端）这三个版本时，每次启动程序都会报有的类找不到，有的资源无法加载，或者是无法构造。

后来把SpringBoot和Kafka后端换成了下面两个版本，2.2.0和2.4.3解决了上面的问题，通过打包程序在服务端启动，都是可以正常调用获取到队列中的信息。

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.0.RELEASE</version>
    </parent>
 
    
    <!-- kafka-2.4.3（后端） -->
    <dependency>
        <groupId>org.springframework.kafka</groupId>
        <artifactId>spring-kafka</artifactId>
        <version>2.4.3.RELEASE</version>
    </dependency>

       后面我想着是不是kafka-2.5.0（服务端）的问题，然后我又用SpringBoot-2.2.0  和kafka-2.4.3（后端），把服务端的kafka换成了2.2.2，刚开始启动zookeeper-server-start.sh的时候是正常的没有报错，但是在启动kafka-server-start.sh的时候，就开始报如下错误。
 

[2020-06-02 10:37:24,947] INFO Initiating client connection, connectString=localhost:2181 sessionTimeout=6000 watcher=kafka.zookeeper.ZooKeeperClient$ZooKeeperClientWatcher$@f1da57d (org.apache.zookeeper.ZooKeeper)
[2020-06-02 10:37:24,978] INFO [ZooKeeperClient] Waiting until connected. (kafka.zookeeper.ZooKeeperClient)
[2020-06-02 10:37:24,983] INFO Opening socket connection to server localhost/<unresolved>:2181. Will not attempt to authenticate using SASL (unknown error) (org.apache.zookeeper.ClientCnxn)
[2020-06-02 10:37:24,992] WARN Session 0x0 for server localhost/<unresolved>:2181, unexpected error, closing socket connection and attempting reconnect (org.apache.zookeeper.ClientCnxn)
java.nio.channels.UnresolvedAddressException
    at java.base/sun.nio.ch.Net.checkAddress(Net.java:139)
    at java.base/sun.nio.ch.SocketChannelImpl.checkRemote(SocketChannelImpl.java:727)
    at java.base/sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:741)
    at org.apache.zookeeper.ClientCnxnSocketNIO.registerAndConnect(ClientCnxnSocketNIO.java:277)
    at org.apache.zookeeper.ClientCnxnSocketNIO.connect(ClientCnxnSocketNIO.java:287)
    at org.apache.zookeeper.ClientCnxn$SendThread.startConnect(ClientCnxn.java:1021)
    at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1064)
[2020-06-02 10:37:26,095] INFO Opening socket connection to server localhost/<unresolved>:2181. Will not attempt to authenticate using SASL (unknown error) (org.apache.zookeeper.ClientCnxn)
[2020-06-02 10:37:26,096] WARN Session 0x0 for server localhost/<unresolved>:2181, unexpected error, closing socket connection and attempting reconnect (org.apache.zookeeper.ClientCnxn)
java.nio.channels.UnresolvedAddressException
    at java.base/sun.nio.ch.Net.checkAddress(Net.java:139)
    at java.base/sun.nio.ch.SocketChannelImpl.checkRemote(SocketChannelImpl.java:727)
    at java.base/sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:741)
    at org.apache.zookeeper.ClientCnxnSocketNIO.registerAndConnect(ClientCnxnSocketNIO.java:277)
    at org.apache.zookeeper.ClientCnxnSocketNIO.connect(ClientCnxnSocketNIO.java:287)
    at org.apache.zookeeper.ClientCnxn$SendThread.startConnect(ClientCnxn.java:1021)
    at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1064)
[2020-06-02 10:37:27,197] INFO Opening socket connection to server localhost/<unresolved>:2181. Will not attempt to authenticate using SASL (unknown error) (org.apache.zookeeper.ClientCnxn)
[2020-06-02 10:37:27,197] WARN Session 0x0 for server localhost/<unresolved>:2181, unexpected error, closing socket connection and attempting reconnect (org.apache.zookeeper.ClientCnxn)
java.nio.channels.UnresolvedAddressException
    at java.base/sun.nio.ch.Net.checkAddress(Net.java:139)
    at java.base/sun.nio.ch.SocketChannelImpl.checkRemote(SocketChannelImpl.java:727)
    at java.base/sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:741)
    at org.apache.zookeeper.ClientCnxnSocketNIO.registerAndConnect(ClientCnxnSocketNIO.java:277)
    at org.apache.zookeeper.ClientCnxnSocketNIO.connect(ClientCnxnSocketNIO.java:287)
    at org.apache.zookeeper.ClientCnxn$SendThread.startConnect(ClientCnxn.java:1021)
    at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1064)
[2020-06-02 10:37:28,298] INFO Opening socket connection to server localhost/<unresolved>:2181. Will not attempt to authenticate using SASL (unknown error) (org.apache.zookeeper.ClientCnxn)
[2020-06-02 10:37:28,298] WARN Session 0x0 for server localhost/<unresolved>:2181, unexpected error, closing socket connection and attempting reconnect (org.apache.zookeeper.ClientCnxn)
java.nio.channels.UnresolvedAddressException
    at java.base/sun.nio.ch.Net.checkAddress(Net.java:139)
    at java.base/sun.nio.ch.SocketChannelImpl.checkRemote(SocketChannelImpl.java:727)
    at java.base/sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:741)
    at org.apache.zookeeper.ClientCnxnSocketNIO.registerAndConnect(ClientCnxnSocketNIO.java:277)
    at org.apache.zookeeper.ClientCnxnSocketNIO.connect(ClientCnxnSocketNIO.java:287)
    at org.apache.zookeeper.ClientCnxn$SendThread.startConnect(ClientCnxn.java:1021)
    at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1064)
[2020-06-02 10:37:29,399] INFO Opening socket connection to server localhost/<unresolved>:2181. Will not attempt to authenticate using SASL (unknown error) (org.apache.zookeeper.ClientCnxn)
[2020-06-02 10:37:29,400] WARN Session 0x0 for server localhost/<unresolved>:2181, unexpected error, closing socket connection and attempting reconnect (org.apache.zookeeper.ClientCnxn)
java.nio.channels.UnresolvedAddressException
    at java.base/sun.nio.ch.Net.checkAddress(Net.java:139)
    at java.base/sun.nio.ch.SocketChannelImpl.checkRemote(SocketChannelImpl.java:727)
    at java.base/sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:741)
    at org.apache.zookeeper.ClientCnxnSocketNIO.registerAndConnect(ClientCnxnSocketNIO.java:277)
    at org.apache.zookeeper.ClientCnxnSocketNIO.connect(ClientCnxnSocketNIO.java:287)
    at org.apache.zookeeper.ClientCnxn$SendThread.startConnect(ClientCnxn.java:1021)
    at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1064)
[2020-06-02 10:37:30,501] INFO Opening socket connection to server localhost/<unresolved>:2181. Will not attempt to authenticate using SASL (unknown error) (org.apache.zookeeper.ClientCnxn)
[2020-06-02 10:37:30,501] WARN Session 0x0 for server localhost/<unresolved>:2181, unexpected error, closing socket connection and attempting reconnect (org.apache.zookeeper.ClientCnxn)
java.nio.channels.UnresolvedAddressException
    at java.base/sun.nio.ch.Net.checkAddress(Net.java:139)
    at java.base/sun.nio.ch.SocketChannelImpl.checkRemote(SocketChannelImpl.java:727)
    at java.base/sun.nio.ch.SocketChannelImpl.connect(SocketChannelImpl.java:741)
    at org.apache.zookeeper.ClientCnxnSocketNIO.registerAndConnect(ClientCnxnSocketNIO.java:277)
    at org.apache.zookeeper.ClientCnxnSocketNIO.connect(ClientCnxnSocketNIO.java:287)
    at org.apache.zookeeper.ClientCnxn$SendThread.startConnect(ClientCnxn.java:1021)
    at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1064)
[2020-06-02 10:37:30,980] INFO [ZooKeeperClient] Closing. (kafka.zookeeper.ZooKeeperClient)
[2020-06-02 10:37:31,602] INFO Opening socket connection to server localhost/<unresolved>:2181. Will not attempt to authenticate using SASL (unknown error) (org.apache.zookeeper.ClientCnxn)
[2020-06-02 10:37:31,705] INFO Session: 0x0 closed (org.apache.zookeeper.ZooKeeper)
[2020-06-02 10:37:31,707] INFO [ZooKeeperClient] Closed. (kafka.zookeeper.ZooKeeperClient)
[2020-06-02 10:37:31,708] INFO EventThread shut down for session: 0x0 (org.apache.zookeeper.ClientCnxn)
[2020-06-02 10:37:31,712] ERROR Fatal error during KafkaServer startup. Prepare to shutdown (kafka.server.KafkaServer)
kafka.zookeeper.ZooKeeperClientTimeoutException: Timed out waiting for connection while in state: CONNECTING
    at kafka.zookeeper.ZooKeeperClient.$anonfun$waitUntilConnected$3(ZooKeeperClient.scala:242)
    at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
    at kafka.utils.CoreUtils$.inLock(CoreUtils.scala:251)
    at kafka.zookeeper.ZooKeeperClient.waitUntilConnected(ZooKeeperClient.scala:238)
    at kafka.zookeeper.ZooKeeperClient.<init>(ZooKeeperClient.scala:96)
    at kafka.zk.KafkaZkClient$.apply(KafkaZkClient.scala:1825)
    at kafka.server.KafkaServer.createZkClient$1(KafkaServer.scala:361)
    at kafka.server.KafkaServer.initZkClient(KafkaServer.scala:385)
    at kafka.server.KafkaServer.startup(KafkaServer.scala:205)
    at kafka.server.KafkaServerStartable.startup(KafkaServerStartable.scala:38)
    at kafka.Kafka$.main(Kafka.scala:75)
    at kafka.Kafka.main(Kafka.scala)
[2020-06-02 10:37:31,713] INFO shutting down (kafka.server.KafkaServer)
[2020-06-02 10:37:31,735] INFO shut down completed (kafka.server.KafkaServer)
[2020-06-02 10:37:31,736] ERROR Exiting Kafka. (kafka.server.KafkaServerStartable)
[2020-06-02 10:37:31,783] INFO shutting down (kafka.server.KafkaServer)
 

最后很难受的解决方案：

把版本换回2.5.0（服务端），又正常了。（也算一种解决方案了。。）

有大佬知道是为什么吗。我看了kafka和zookeeper的启动配置文件，都是差不多的，除了2.5.0有几个新的配置项，其他内容是一样的，修改的内容只有增了一个：advertised.listeners=PLAINTEXT://服务器的ip:9092