Question

我安装了一个四节点hadoop集群。在hadoop Webui中我可以看到所有数据节点和名称节点都已启动并运行。但是，当我在蜂巢中运行select count(*) from table_name;时，查询就会卡住。

hive> select count(*) from test_hive2;
Query ID = dssbp_20160804124833_ff269da1-6b91-4e46-a1df-460603a5cb98
Total jobs = 1
Launching Job 1 out of 1
Number of reduce tasks determined at compile time: 1
In order to change the average load for a reducer (in bytes):
  set hive.exec.reducers.bytes.per.reducer=<number>
In order to limit the maximum number of reducers:
  set hive.exec.reducers.max=<number>
In order to set a constant number of reducers:
  set mapreduce.job.reduces=<number>

我在datanode节点管理器日志和配置单元日志中不断得到的错误是：

2016-08-04 12:33:31,474 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: namenode1/172.18.128.24:6005. Already tried 8 time(s); retry policy is RetryUpToMaximumCountWithFixedSleep(maxRetries=10, sleepTime=1000 MILLISECONDS)

我检查过的事情：

1.可以从datanode telnet到name节点 2.可以执行hadoop put和get命令 3.可以在配置单元中创建表并将数据加载到它。

cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
#::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
172.18.128.24   namenode1 mycluster
172.18.128.25  namenode2
172.18.128.26  datanode1
172.18.128.27  datanode2

如果任何人都能提出可能的解决方案，那将是很有帮助的。

此致兰詹

Answer 1

我能够解决该问题，因为资源管理器存在一些问题，而且从数据节点无法连接到172.18.128.24:6005此端口。

虽然Hadoop已经启动，但是地图减少了工作

1 个答案: