Hello Jay, My input is just a csv file (created it myself), so I am sure it is not compressed in any way. Also, the same input works when I use the standalone example (using the hadoop executable in the bin folder). When I try to integrate it in a larger java program it fails.... :(
Regards, Bas On Sun, Apr 15, 2012 at 2:30 PM, JAX <jayunit...@gmail.com> wrote: > That is odd---- why would it crash when your m/r job did not rely on snappy? > > One possibility : Maybe because your input is snappy compressed, Hadoop is > detecting that compression, and trying to use the snappy codec to decompress.? > > Jay Vyas > MMSB > UCHC > > On Apr 15, 2012, at 5:08 AM, Bas Hickendorff <hickendorff...@gmail.com> wrote: > >> Hello John, >> >> I did restart them (in fact, I did a full reboot of the machine). The >> error is still there. >> >> I guess my question is: is it expected that Hadoop needs to do >> something with the Snappycodec when mapred.compress.map.output is set >> to false? >> >> Regards, >> >> Bas >> >> On Sun, Apr 15, 2012 at 12:04 PM, john smith <js1987.sm...@gmail.com> wrote: >>> 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 >>>>> >>>>
