It isn't possible to do this since 0.21+ broke MR binary compatibility aside of some other minor API changes. You do not need to rewrite your application/job in most cases, but you do have to recompile it against the target cluster's libraries to get a binary compatible jar you can run.
On Thu, Mar 14, 2013 at 6:42 PM, Zheyi RONG <[email protected]> wrote: > Hi, > > Is it possible to run a jar built with hadoop new apis (hadoop 0.22.0) on > a cluster deployed with CDH 3 (hadoop 0.20.2) ? > The jar uses some hadoop Api (e.g. > org.apache.hadoop.mapreduce.lib.chain.ChainMapper) that hadoop 0.20.2 does > not have. > > I ran it, but hadoop complains: > Exception in thread "main" java.lang.IncompatibleClassChangeError: > Implementing class > at java.lang.ClassLoader.defineClass1(Native Method) > at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631) > at java.lang.ClassLoader.defineClass(ClassLoader.java:615) > at > java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141) > at java.net.URLClassLoader.defineClass(URLClassLoader.java:283) > at java.net.URLClassLoader.access$000(URLClassLoader.java:58) > at java.net.URLClassLoader$1.run(URLClassLoader.java:197) > at java.security.AccessController.doPrivileged(Native Method) > at java.net.URLClassLoader.findClass(URLClassLoader.java:190) > at java.lang.ClassLoader.loadClass(ClassLoader.java:306) > at java.lang.ClassLoader.loadClass(ClassLoader.java:247) > at > org.apache.hadoop.mapreduce.lib.chain.ChainMapper.addMapper(ChainMapper.java:126) > at driver.ChainDriver.run(ChainDriver.java:146) > at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65) > at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:79) > at driver.ChainDriver.main(ChainDriver.java:173) > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) > at > sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) > at java.lang.reflect.Method.invoke(Method.java:597) > at org.apache.hadoop.util.RunJar.main(RunJar.java:197) > > > Is there any workaround? I really do not want to rewrite my project... > > Thank you very much. > > Regards, > > Zheyi. > -- Harsh J
