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https://issues.apache.org/jira/browse/CASSANDRA-7200?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14057879#comment-14057879
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Ala' Alkhaldi commented on CASSANDRA-7200:
------------------------------------------
The slowness is caused by using vnodes at the cassandra server which is not
recommended for the hadoop case. For instance, WordCountSetup relies on the
number of returned vnodes to determine the sleep time after creating the
keyspace which turned to be 256 seconds in current default installation of
Cassandra. I updated the README file to mention that disabaling vnodes is
recommended.
The Attached 7200_v2.txt includes the README update as well as the changes in
7200_v1.txt changes.
I also checked Cassandra 2.0. The hadoop_word_count example works fine, but the
cql3 word count has a bug that is already solved as I mentioned in the above
comment.
> word count broken
> -----------------
>
> Key: CASSANDRA-7200
> URL: https://issues.apache.org/jira/browse/CASSANDRA-7200
> Project: Cassandra
> Issue Type: Bug
> Components: Examples
> Reporter: Brandon Williams
> Assignee: Ala' Alkhaldi
> Fix For: 2.0.10
>
> Attachments: 7200_v1.txt, 7200_v2.txt
>
>
> word_count_setup hangs forever, and word_count loops forever with this
> exception:
> {noformat}
> DEBUG 17:52:42,875 java.io.IOException: config(config)
> at org.apache.hadoop.conf.Configuration.<init>(Configuration.java:260)
> at org.apache.hadoop.mapred.JobConf.<init>(JobConf.java:341)
> at org.apache.hadoop.mapreduce.JobContext.<init>(JobContext.java:76)
> at
> org.apache.hadoop.mapreduce.TaskAttemptContext.<init>(TaskAttemptContext.java:35)
> at
> org.apache.hadoop.mapreduce.TaskInputOutputContext.<init>(TaskInputOutputContext.java:44)
> at org.apache.hadoop.mapreduce.MapContext.<init>(MapContext.java:43)
> at org.apache.hadoop.mapreduce.Mapper$Context.<init>(Mapper.java:105)
> at sun.reflect.GeneratedConstructorAccessor14.newInstance(Unknown
> Source)
> at
> sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
> at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
> at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:759)
> at org.apache.hadoop.mapred.MapTask.run(MapTask.java:370)
> at
> org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:212)
> {noformat}
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