Thanks.
The native snappy libraries I have installed. However, I use the
normal jars that you get when downloading Hadoop, I am not compiling
Hadoop myself.
I do not want to use the snappy codec (I don't care about compression
at the moment), but it seems it is needed anyway? I added this to the
mapred-site.xml:
<property>
<name>mapred.compress.map.output</name>
<value>false</value>
</property>
But it still fails with the error of my previous email (SnappyCodec not found).
Regards,
Bas
On Sat, Apr 14, 2012 at 6:30 PM, Vinod Kumar Vavilapalli
<vino...@hortonworks.com> wrote:
>
> Hadoop has integrated snappy via installed native libraries instead of
> snappy-java.jar (ref https://issues.apache.org/jira/browse/HADOOP-7206)
> - You need to have the snappy system libraries (snappy and snappy-devel)
> installed before you compile hadoop. (RPMs are available on the web,
> http://pkgs.org/centos-5-rhel-5/epel-i386/21/ for example)
> - When you build hadoop, you will need to compile the native libraries(by
> passing -Dcompile.native=true to ant) to avail snappy support.
> - You also need to make sure that snappy system library is available on the
> library path for all mapreduce tasks at runtime. Usually if you install them
> on /usr/lib or /usr/local/lib, it should work.
>
> HTH,
> +Vinod
>
> On Apr 14, 2012, at 4:36 AM, Bas Hickendorff wrote:
>
>> Hello,
>>
>> When I start a map-reduce job, it starts, and after a short while,
>> fails with the error below (SnappyCodec not found).
>>
>> I am currently starting the job from other Java code (so the Hadoop
>> executable in the bin directory is not used anymore), but in principle
>> this seems to work (in the admin of the Jobtracker the job shows up
>> when it starts). However after a short while the map task fails with:
>>
>>
>> java.lang.IllegalArgumentException: Compression codec
>> org.apache.hadoop.io.compress.SnappyCodec not found.
>> at
>> org.apache.hadoop.io.compress.CompressionCodecFactory.getCodecClasses(CompressionCodecFactory.java:96)
>> at
>> org.apache.hadoop.io.compress.CompressionCodecFactory.<init>(CompressionCodecFactory.java:134)
>> at
>> org.apache.hadoop.mapreduce.lib.input.LineRecordReader.initialize(LineRecordReader.java:62)
>> at
>> org.apache.hadoop.mapred.MapTask$NewTrackingRecordReader.initialize(MapTask.java:522)
>> at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:763)
>> at org.apache.hadoop.mapred.MapTask.run(MapTask.java:370)
>> at org.apache.hadoop.mapred.Child$4.run(Child.java:255)
>> at java.security.AccessController.doPrivileged(Native Method)
>> at javax.security.auth.Subject.doAs(Subject.java:416)
>> at
>> org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1093)
>> at org.apache.hadoop.mapred.Child.main(Child.java:249)
>> Caused by: java.lang.ClassNotFoundException:
>> org.apache.hadoop.io.compress.SnappyCodec
>> at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
>> at java.security.AccessController.doPrivileged(Native Method)
>> at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
>> at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
>> at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
>> at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
>> at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:334)
>> at java.lang.Class.forName0(Native Method)
>> at java.lang.Class.forName(Class.java:264)
>> at
>> org.apache.hadoop.conf.Configuration.getClassByName(Configuration.java:820)
>> at
>> org.apache.hadoop.io.compress.CompressionCodecFactory.getCodecClasses(CompressionCodecFactory.java:89)
>> ... 10 more
>>
>>
>> I confirmed that the SnappyCodec class is present in the
>> hadoop-core-1.0.2.jar, and the snappy-java-1.0.4.1.jar is present as
>> well. The directory of those jars is on the HADOOP_CLASSPATH, but it
>> seems it still cannot find it. I also checked that the config files of
>> Hadoop are read. I run all nodes on localhost.
>>
>> Any suggestions on what could be the cause of the issue?
>>
>> Regards,
>>
>> Bas
>
