Hadoop Error - All data nodes are aborting

Question

I am using Hadoop 2.3.0 version. Sometimes when I execute the Map reduce job, the below errors will get displayed.

14/08/10 12:14:59 INFO mapreduce.Job: Task Id : attempt_1407694955806_0002_m_000780_0, Status : FAILED
Error: java.io.IOException: All datanodes 192.168.30.2:50010 are bad. Aborting...
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.setupPipelineForAppendOrRecovery(DFSOutputStream.java:1023)
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.processDatanodeError(DFSOutputStream.java:838)
    at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.run(DFSOutputStream.java:483)

When I try to check the log files for these failed tasks, the log folder for this task will be empty.

I am not able to understand the reason behind this error. Could someone please let me know how to resolve this issue. Thanks for your help.

Answer 1

You seem to be hitting the open file handles limit of your user. This is a pretty common issue, and can be cleared in most cases by increasing the ulimit values (its mostly 1024 by default, easily exhaustible by multi-out jobs like yours).