Can you restart tasktrackers once and run the job again? It refreshes the class path.
On Sun, Apr 15, 2012 at 11:58 AM, Bas Hickendorff <hickendorff...@gmail.com>wrote: > 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 > > >
