# 创建Kafka Topic时报错"NoNode for /brokers/ids"
#### 问题背景与现象
在使用Kafka客户端命令创建Topic时，发现Topic无法被创建。
```
kafka-topics.sh --create  --replication-factor 1 --partitions 2 --topic test --zookeeper 192.168.234.231:2181
```
提示错误NoNodeException: KeeperErrorCode = NoNode for /brokers/ids。
具体如下：
```
Error while executing topic command : org.apache.zookeeper.KeeperException$NoNodeException: KeeperErrorCode = NoNode for /brokers/ids
[2017-09-17 16:35:28,520] ERROR org.I0Itec.zkclient.exception.ZkNoNodeException: org.apache.zookeeper.KeeperException$NoNodeException: KeeperErrorCode = NoNode for /brokers/ids
at org.I0Itec.zkclient.exception.ZkException.create(ZkException.java:47)
at org.I0Itec.zkclient.ZkClient.retryUntilConnected(ZkClient.java:995)
at org.I0Itec.zkclient.ZkClient.getChildren(ZkClient.java:675)
at org.I0Itec.zkclient.ZkClient.getChildren(ZkClient.java:671)
at kafka.utils.ZkUtils.getChildren(ZkUtils.scala:541)
at kafka.utils.ZkUtils.getSortedBrokerList(ZkUtils.scala:176)
at kafka.admin.AdminUtils$.createTopic(AdminUtils.scala:235)
at kafka.admin.TopicCommand$.createTopic(TopicCommand.scala:105)
at kafka.admin.TopicCommand$.main(TopicCommand.scala:60)
at kafka.admin.TopicCommand.main(TopicCommand.scala)
Caused by: org.apache.zookeeper.KeeperException$NoNodeException: KeeperErrorCode = NoNode for /brokers/ids
at org.apache.zookeeper.KeeperException.create(KeeperException.java:115)
at org.apache.zookeeper.KeeperException.create(KeeperException.java:51)
at org.apache.zookeeper.ZooKeeper.getChildren(ZooKeeper.java:2256)
at org.apache.zookeeper.ZooKeeper.getChildren(ZooKeeper.java:2284)
at org.I0Itec.zkclient.ZkConnection.getChildren(ZkConnection.java:114)
at org.I0Itec.zkclient.ZkClient$4.call(ZkClient.java:678)
at org.I0Itec.zkclient.ZkClient$4.call(ZkClient.java:675)
at org.I0Itec.zkclient.ZkClient.retryUntilConnected(ZkClient.java:985)
... 8 more
 (kafka.admin.TopicCommand$)
```
#### 可能原因
- Kafka服务处于停止状态。
- 客户端命令中ZooKeeper地址参数配置错误。
 
#### 原因分析
1. 使用客户端命令，打印NoNodeException异常。
   ```
   Error while executing topic command : org.apache.zookeeper.KeeperException$NoNodeException: KeeperErrorCode = NoNode for /brokers/ids
   [2017-09-17 16:35:28,520] ERROR org.I0Itec.zkclient.exception.ZkNoNodeException: org.apache.zookeeper.KeeperException$NoNodeException: KeeperErrorCode = NoNode for /brokers/ids
   at org.I0Itec.zkclient.exception.ZkException.create(ZkException.java:47)
   at org.I0Itec.zkclient.ZkClient.retryUntilConnected(ZkClient.java:995)
   at org.I0Itec.zkclient.ZkClient.getChildren(ZkClient.java:675)
   at org.I0Itec.zkclient.ZkClient.getChildren(ZkClient.java:671)
   at kafka.utils.ZkUtils.getChildren(ZkUtils.scala:541)
   at kafka.utils.ZkUtils.getSortedBrokerList(ZkUtils.scala:176)
   at kafka.admin.AdminUtils$.createTopic(AdminUtils.scala:235)
   at kafka.admin.TopicCommand$.createTopic(TopicCommand.scala:105)
   at kafka.admin.TopicCommand$.main(TopicCommand.scala:60)
   at kafka.admin.TopicCommand.main(TopicCommand.scala)
   ```
   
2. 通过Manager查看Kafka服务是否处于正常状态。
3. 检查客户端命令中ZooKeeper地址是否正确，访问ZooKeeper上所存放的Kafka信息，其路径（Znode）应该加上/kafka，发现配置中缺少/kafka：
   ```
   [root@10-10-144-2 client]# 
   kafka-topics.sh --create  --replication-factor 1 --partitions 2 --topic test --zookeeper 192.168.234.231:2181
   ```
   
 
#### 解决办法
1. 保证Kafka服务处于正常状态。
2. 创建命令中ZooKeeper地址信息需要添加/kafka。 
   ```
   [root@10-10-144-2 client]# 
   kafka-topics.sh --create  --replication-factor 1 --partitions 2 --topic test --zookeeper 192.168.234.231:2181/kafka
   ```