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MapReduce, mail # user - Re: Hadoop C++ HDFS test running Exception


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Re: Hadoop C++ HDFS test running Exception
Harsh J 2014-01-14, 02:39
I've found in past that the native code runtime somehow doesn't
support wildcarded classpaths. If you add the jars explicitly to the
CLASSPATH, your app will work. You could use a simple shell loop such
as at one of my random examples at
https://github.com/QwertyManiac/cdh4-libhdfs-example/blob/master/exec.sh#L3
to populate it easily instead of doing it by hand.

On Mon, Jan 13, 2014 at 3:36 PM, Andrea Barbato <[EMAIL PROTECTED]> wrote:
> I'm working with Hadoop 2.2.0 and trying to run this hdfs_test.cpp
> application:
>
> #include "hdfs.h"
>
> int main(int argc, char **argv) {
>
>     hdfsFS fs = hdfsConnect("default", 0);
>     const char* writePath = "/tmp/testfile.txt";
>     hdfsFile writeFile = hdfsOpenFile(fs, writePath, O_WRONLY|O_CREAT, 0, 0,
> 0);
>     if(!writeFile) {
>           fprintf(stderr, "Failed to open %s for writing!\n", writePath);
>           exit(-1);
>     }
>     char* buffer = "Hello, World!";
>     tSize num_written_bytes = hdfsWrite(fs, writeFile, (void*)buffer,
> strlen(buffer)+1);
>     if (hdfsFlush(fs, writeFile)) {
>            fprintf(stderr, "Failed to 'flush' %s\n", writePath);
>           exit(-1);
>     }
>    hdfsCloseFile(fs, writeFile);
> }
>
> I compiled it but when I'm running it with ./hdfs_test I have this:
>
> loadFileSystems error:
> (unable to get stack trace for java.lang.NoClassDefFoundError exception:
> ExceptionUtils::getStackTrace error.)
> hdfsBuilderConnect(forceNewInstance=0, nn=default, port=0,
> kerbTicketCachePath=(NULL), userName=(NULL)) error:
> (unable to get stack trace for java.lang.NoClassDefFoundError exception:
> ExceptionUtils::getStackTrace error.)
> hdfsOpenFile(/tmp/testfile.txt): constructNewObjectOfPath error:
> (unable to get stack trace for java.lang.NoClassDefFoundError exception:
> ExceptionUtils::getStackTrace error.)
> Failed to open /tmp/testfile.txt for writing!
>
> Maybe is a problem with the classpath. My $HADOOP_HOME is /usr/local/hadoop
> and actually this is my variable *CLASSPATH*:
>
> echo $CLASSPATH
> /usr/local/hadoop/etc/hadoop:/usr/local/hadoop/share/hadoop/common/lib/*:/usr/local/hadoop/share/hadoop/common/*:/usr/local/hadoop/share/hadoop/hdfs:/usr/local/hadoop/share/hadoop/hdfs/lib/*:/usr/local/hadoop/share/hadoop/hdfs/*:/usr/local/hadoop/share/hadoop/yarn/lib/*:/usr/local/hadoop/share/hadoop/yarn/*:/usr/local/hadoop/share/hadoop/mapreduce/lib/*:/usr/local/hadoop/share/hadoop/mapreduce/*:/contrib/capacity-scheduler/*.jar
>
>
> Any help is appreciated.. thanks

--
Harsh J