Hi I have very strange problem regarding ClassNotFoundException for vertex output format (my own implementation). When I run my program I get an exception:
java.lang.RuntimeException: java.lang.RuntimeException: java.lang.ClassNotFoundException: org.test.giraph.utils.writers.generic.SamplingOutputFormat at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:898) at org.apache.giraph.graph.BspUtils.getVertexOutputFormatClass(BspUtils.java:134) at org.apache.giraph.bsp.BspOutputFormat.getOutputCommitter(BspOutputFormat.java:56) at org.apache.hadoop.mapred.Task.initialize(Task.java:490) at org.apache.hadoop.mapred.MapTask.run(MapTask.java:352) at org.apache.hadoop.mapred.Child$4.run(Child.java:259) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:396) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1059) at org.apache.hadoop.mapred.Child.main(Child.java:253) I have came across this exception earlier and I've solved it with the use of "-libjars" parameter in which I pass the path to giraph-0.2-SNAPSHOT-jar-with-dependencies.jar and myJob.jar (which I execute). This solution has worked very nice for me, I used it in a number of programs (with my own InputFormat and OutputFormat), till today. I've created a small program (TestVertex) to test one solution and I used a NewOutputFormat created for the test program. When I received ClassNotFoundException I thought I have made a mistake somewhere, so I've checked. I couldn't find any bugs, so I replaced the NewOutputFormat with a one used across other programs (OldOutputFormat). I got the same exception. for the old one as well. I have cleaned and build the whole myJob.jar and I was still getting the exception (both for New and Old). So I tested the original program (same myJob.jar) in which I'm using the OldOutputFormat and the program works. Since then I tried couple of OutputFormat and none of them worked (ClassNotFoundException). Then I commented the whole "body" of TestVertex and I've paste some old working code (with OldOutputFormat). The only difference between TestVertex and old working code is the class name. Final I received the ClassNotFoundException again (again the original code works, I've tested it). It looks like only the TestVertex class has this problem, no matter what OutputFormat I will use I am always getting the exception (all other programs which use my OutputFormats work correctly). Another interesting aspect is the fact that if I use Giraph provided OutputFormat (for example JsonBase64VertexOutputFormat) I get a ClassNotFoundException but for the TestVertex. I've checked the myJob.jar and all mentioned classes are present in the jar in correct places. I run out of ideas any suggestions will be greatly appreciated. Some conf info I am using an older Giraph revision (1340869) and Hadoop 0.20.203 in pseudo-distributed mode. I have created the HADOOP_CLASSPATH which holds path to giraph-0.2-SNAPSHOT-jar-with-dependencies.jar. I execute job in the following way: hadoop jar myJob.jar org.test.giraph.Test -libjars /path/to/giraph-0.2-SNAPSHOT-jar-with-dependencies.jar,/path/to/myJob.jar /path/to/input /path/to/output <job params> regards marcin