I installed a four node hadoop cluster.In hadoop Webui i can see all the datanodes and namenodes are up and running. But when i am running select count(*) from table_name; in hive the query is getting stuck.
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>
The error that i am continiously getting in my datanode node manager logs and hive logs is:
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)
Things i have checked:
1.Can do telnet from datanode to name node.
2.Can execute hadoop put and get command.
3.can create tables in hive and load data to it.
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
It would be great help if any one can suggest the possible solutions.
Regards, Ranjan
I could able to solve that issue as there was some issue with resource manager and from data node it was not able to connect to 172.18.128.24:6005 this port.