Hadoop C++ HDFS test running Exception

[Andrea Barbato]

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]

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.

I'm working with Hadoop 2.2.0 and trying to run this hdfs_test.cpp
#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);
}
ExceptionUtils::getStackTrace error.)
hdfsBuilderConnect(forceNewInstance=0, nn=default, port=0,
ExceptionUtils::getStackTrace error.)
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
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

[Andrea Barbato]

Thanks for the answer, but i can't find the client folder that contains the
files .jar: /usr/lib/hadoop/client/*.jar.
I'm using hadoop 2.2.0, can you tell me the name of this folder in that
version?

Post by Harsh J
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.

I'm working with Hadoop 2.2.0 and trying to run this hdfs_test.cpp
#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);
}
ExceptionUtils::getStackTrace error.)
hdfsBuilderConnect(forceNewInstance=0, nn=default, port=0,
ExceptionUtils::getStackTrace error.)
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

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