我正在使用Kafka 0.8.2-beta，并且有2个Ubuntu 14虚拟机：
- 172.30.141.127正在运行动物园管理员
- 172.30.141.184 正在运行 Kafka 代理
我正在启动 Zookeeper 实例，如果一切正常。然后我尝试启动代理并将其连接到 172.30.141.127：2181。它似乎能够在特定端口上连接并建立会话，但由于似乎未记录的某些异常，它失去了连接。
代理输出：
[2015-01-19 11:03:55,029] INFO Client environment:java.io.tmpdir=/tmp (org.apache.zookeeper.ZooKeeper)
[2015-01-19 11:03:55,030] INFO Client environment:java.compiler=<NA> (org.apache.zookeeper.ZooKeeper)
[2015-01-19 11:03:55,031] INFO Client environment:os.name=Linux (org.apache.zookeeper.ZooKeeper)
[2015-01-19 11:03:55,031] INFO Client environment:os.arch=i386 (org.apache.zookeeper.ZooKeeper)
[2015-01-19 11:03:55,032] INFO Client environment:os.version=3.16.0-23-generic (org.apache.zookeeper.ZooKeeper)
[2015-01-19 11:03:55,033] INFO Client environment:user.name=root (org.apache.zookeeper.ZooKeeper)
[2015-01-19 11:03:55,033] INFO Client environment:user.home=/root (org.apache.zookeeper.ZooKeeper)
[2015-01-19 11:03:55,037] INFO Client environment:user.dir=/home/osboxes/Desktop/kafka_2.11-0.8.2-beta (org.apache.zookeeper.ZooKeeper)
[2015-01-19 11:03:55,039] INFO Initiating client connection, connectString=172.30.141.127:2181 sessionTimeout=6000 watcher=org.I0Itec.zkclient.ZkClient@1ecf473 (org.apache.zookeeper.ZooKeeper)
[2015-01-19 11:03:55,129] INFO Opening socket connection to server 172.30.141.127/172.30.141.127:2181. Will not attempt to authenticate using SASL (unknown error) (org.apache.zookeeper.ClientCnxn)
[2015-01-19 11:03:55,186] INFO Socket connection established to 172.30.141.127/172.30.141.127:2181, initiating session (org.apache.zookeeper.ClientCnxn)
[2015-01-19 11:03:55,203] WARN Session 0x0 for server 172.30.141.127/172.30.141.127:2181, unexpected error, closing socket connection and attempting reconnect (org.apache.zookeeper.ClientCnxn)
java.io.IOException: Connection reset by peer
at sun.nio.ch.FileDispatcherImpl.read0(Native Method)
at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:39)
at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
at sun.nio.ch.IOUtil.read(IOUtil.java:192)
at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:379)
at org.apache.zookeeper.ClientCnxnSocketNIO.doIO(ClientCnxnSocketNIO.java:68)
at org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:366)
at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1081)
[2015-01-19 11:03:56,552] INFO Opening socket connection to server 172.30.141.127/172.30.141.127:2181. Will not attempt to authenticate using SASL (unknown error) (org.apache.zookeeper.ClientCnxn)
[2015-01-19 11:03:56,555] INFO Socket connection established to 172.30.141.127/172.30.141.127:2181, initiating session (org.apache.zookeeper.ClientCnxn)
[2015-01-19 11:03:56,567] WARN Session 0x0 for server 172.30.141.127/172.30.141.127:2181, unexpected error, closing socket connection and attempting reconnect (org.apache.zookeeper.ClientCnxn)
java.io.IOException: Connection reset by peer
at sun.nio.ch.FileDispatcherImpl.read0(Native Method)
at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:39)
at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
at sun.nio.ch.IOUtil.read(IOUtil.java:192)
at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:379)
at org.apache.zookeeper.ClientCnxnSocketNIO.doIO(ClientCnxnSocketNIO.java:68)
at org.apache.zookeeper.ClientCnxnSocketNIO.doTransport(ClientCnxnSocketNIO.java:366)
at org.apache.zookeeper.ClientCnxn$SendThread.run(ClientCnxn.java:1081)
[2015-01-19 11:03:57,131] INFO Terminate ZkClient event thread. (org.I0Itec.zkclient.ZkEventThread)
[2015-01-19 11:03:58,075] INFO Opening socket connection to server 172.30.141.127/172.30.141.127:2181. Will not attempt to authenticate using SASL (unknown error) (org.apache.zookeeper.ClientCnxn)
[2015-01-19 11:03:58,077] INFO Socket connection established to 172.30.141.127/172.30.141.127:2181, initiating session (org.apache.zookeeper.ClientCnxn)
[2015-01-19 11:03:58,195] INFO Session: 0x0 closed (org.apache.zookeeper.ZooKeeper)
[2015-01-19 11:03:58,196] INFO EventThread shut down (org.apache.zookeeper.ClientCnxn)
[2015-01-19 11:03:58,251] FATAL [Kafka Server 1], Fatal error during KafkaServer startup. Prepare to shutdown (kafka.server.KafkaServer)
org.I0Itec.zkclient.exception.ZkTimeoutException: Unable to connect to zookeeper server within timeout: 2000
at org.I0Itec.zkclient.ZkClient.connect(ZkClient.java:880)
at org.I0Itec.zkclient.ZkClient.<init>(ZkClient.java:98)
at org.I0Itec.zkclient.ZkClient.<init>(ZkClient.java:84)
at kafka.server.KafkaServer.initZk(KafkaServer.scala:157)
at kafka.server.KafkaServer.startup(KafkaServer.scala:83)
at kafka.server.KafkaServerStartable.startup(KafkaServerStartable.scala:28)
at kafka.Kafka$.main(Kafka.scala:46)
at kafka.Kafka.main(Kafka.scala)
[2015-01-19 11:03:58,279] INFO [Kafka Server 1], shutting down (kafka.server.KafkaServer)
[2015-01-19 11:03:58,295] INFO [Kafka Server 1], shut down completed (kafka.server.KafkaServer)
[2015-01-19 11:03:58,308] FATAL Fatal error during KafkaServerStartable startup. Prepare to shutdown (kafka.server.KafkaServerStartable)
org.I0Itec.zkclient.exception.ZkTimeoutException: Unable to connect to zookeeper server within timeout: 2000
at org.I0Itec.zkclient.ZkClient.connect(ZkClient.java:880)
at org.I0Itec.zkclient.ZkClient.<init>(ZkClient.java:98)
at org.I0Itec.zkclient.ZkClient.<init>(ZkClient.java:84)
at kafka.server.KafkaServer.initZk(KafkaServer.scala:157)
at kafka.server.KafkaServer.startup(KafkaServer.scala:83)
at kafka.server.KafkaServerStartable.startup(KafkaServerStartable.scala:28)
at kafka.Kafka$.main(Kafka.scala:46)
at kafka.Kafka.main(Kafka.scala)
[2015-01-19 11:03:58,335] INFO [Kafka Server 1], shutting down (kafka.server.KafkaServer)
Zookeper 输出：
[2015-01-19 11:03:55,245] INFO Accepted socket connection from /172.30.141.184:54089 (org.apache.zookeeper.server.NIOServerCnxnFactory)
[2015-01-19 11:03:55,315] WARN Exception causing close of session 0x0 due to java.io.IOException: Connection reset by peer (org.apache.zookeeper.server.NIOServerCnxn)
[2015-01-19 11:03:55,329] INFO Closed socket connection for client /172.30.141.184:54089 (no session established for client) (org.apache.zookeeper.server.NIOServerCnxn)
[2015-01-19 11:03:56,613] INFO Accepted socket connection from /172.30.141.184:54090 (org.apache.zookeeper.server.NIOServerCnxnFactory)
[2015-01-19 11:03:56,615] WARN Exception causing close of session 0x0 due to java.io.IOException: Connection reset by peer (org.apache.zookeeper.server.NIOServerCnxn)
[2015-01-19 11:03:56,617] INFO Closed socket connection for client /172.30.141.184:54090 (no session established for client) (org.apache.zookeeper.server.NIOServerCnxn)
[2015-01-19 11:03:58,133] INFO Accepted socket connection from /172.30.141.184:54091 (org.apache.zookeeper.server.NIOServerCnxnFactory)
[2015-01-19 11:03:58,134] WARN Exception causing close of session 0x0 due to java.io.IOException: Connection reset by peer (org.apache.zookeeper.server.NIOServerCnxn)
[2015-01-19 11:03:58,135] INFO Closed socket connection for client /172.30.141.184:54091 (no session established for client) (org.apache.zookeeper.server.NIOServerCnxn)
Ping 在 2 台机器之间工作。Telnet 到 2181 是一种工作，因为它连接，但不时断开连接。这让我认为问题出在 Zookeeper 实例上。这两个进程都以根用户身份启动。
知道为什么会这样吗？谢谢
您可能达到了每个主机的最大连接数。
如果您的动物园管理员日志中有[NIOServerCxn.Factory:0.0.0.0/0.0.0.0:2181:NIOServerCnxn$Factory@247] - Too many connections from /127.0.0.1 - max is 10，就会发生这种情况。
通过在conf/zoo.cfg中设置maxClientCnxns=[something more than 10; 0 for unlimited]来修复它。
Docs （搜索 maxClientCnxns）
不知道警告，但我有同样的错误问题
org.I0Itec.zkclient.exception.ZkTimeoutException: Unable to connect to zookeeper server within timeout: 2000
at org.I0Itec.zkclient.ZkClient.connect(ZkClient.java:880)
....
就我而言，当我设置生产者和消费者时，我提供了错误的 ip/端口。当我将其更改为更正一个时：
bin/kafka-console-producer.sh --broker-list kafka_ip:kafka_port --topic test
bin/kafka-console-consumer.sh --zookeeper zookeeper_id:zookeper_port --topic test --from-beginning
我的问题解决了。
由@RickyA回答"您可能达到了每个主机的最大连接数。"尝试清除您的日志文件夹，在我的例子中是 F：\tmp\kafka-logs。