Hi Shahab, Thanks. That helped.
Regards, Shambhavi On Thu, Apr 30, 2015 at 10:18 AM, Shahab Yunus <[email protected]> wrote: > The reason is that the Json parsing code is in a 3rd party library which > is not included in the default map reduce/hadoop distribution. You have to > add them in your classpath at *runtime*. There are multiple ways to do it > (which also depends upon how you plan to run and package/deploy your code.) > > Check out this: > > https://hadoopi.wordpress.com/2014/06/05/hadoop-add-third-party-libraries-to-mapreduce-job/ > > http://blog.cloudera.com/blog/2011/01/how-to-include-third-party-libraries-in-your-map-reduce-job/ > > Regards, > Shahab > > On Thu, Apr 30, 2015 at 1:01 PM, Shambhavi Punja <[email protected]> wrote: > >> Hi, >> >> I am working on an assignment on Hadoop Map reduce. I am very new to Map >> Reduce. >> >> The assignment has many sections but for now I am trying to parse JSON >> data. >> >> The input(i.e. value) to the map function is a single record of the form >> xyz, {'abc’:’pqr1’,'abc2’:'pq1, pq2’}, {‘key’:'value1’} >> I am interested only in the getting the frequency of value1. >> >> Following is the map- reduce job. >> >> public static class Map extends MapReduceBase implements >> Mapper<LongWritable, Text, Text, IntWritable> { >> private final static IntWritable one = new IntWritable(1); >> private Text word = new Text(); >> >> >> public void map(LongWritable key, Text value, >> OutputCollector<Text, IntWritable> output, Reporter reporter) throws >> IOException { >> String line = value.toString(); >> String[] tuple = line.split("(?<=\\}),\\s"); >> try{ >> JSONObject obj = new JSONObject(tuple[1]); >> String id = obj.getString(“key"); >> word.set(id); >> output.collect(word, one); >> } >> catch(JSONException e){ >> e.printStackTrace(); >> } >> } >> } >> >> >> >> >> public static class Reduce extends MapReduceBase implements >> Reducer<Text, IntWritable, Text, IntWritable> { >> public void reduce(Text key, Iterator<IntWritable> values, >> OutputCollector<Text, IntWritable> output, Reporter reporter) throws >> IOException { >> int sum = 0; >> while (values.hasNext()) { >> sum += values.next().get(); >> } >> output.collect(key, new IntWritable(sum)); >> } >> } >> >> I successfully compiled the java code using the json and hadoop jars. >> Created a jar. But wen I run the Hadoop command I am getting the following >> exceptions. >> >> >> 15/04/30 00:36:49 WARN util.NativeCodeLoader: Unable to load >> native-hadoop library for your platform... using builtin-java classes where >> applicable >> 15/04/30 00:36:49 WARN mapred.JobClient: Use GenericOptionsParser for >> parsing the arguments. Applications should implement Tool for the same. >> 15/04/30 00:36:49 WARN snappy.LoadSnappy: Snappy native library not loaded >> 15/04/30 00:36:49 INFO mapred.FileInputFormat: Total input paths to >> process : 1 >> 15/04/30 00:36:49 INFO mapred.JobClient: Running job: >> job_local1121514690_0001 >> 15/04/30 00:36:49 INFO mapred.LocalJobRunner: Waiting for map tasks >> 15/04/30 00:36:49 INFO mapred.LocalJobRunner: Starting task: >> attempt_local1121514690_0001_m_000000_0 >> 15/04/30 00:36:49 INFO mapred.Task: Using ResourceCalculatorPlugin : null >> 15/04/30 00:36:49 INFO mapred.MapTask: Processing split: >> file:/Users/Shamvi/gumgum/jars/input/ab1.txt:0+305 >> 15/04/30 00:36:49 INFO mapred.MapTask: numReduceTasks: 1 >> 15/04/30 00:36:49 INFO mapred.MapTask: io.sort.mb = 100 >> 15/04/30 00:36:49 INFO mapred.MapTask: data buffer = 79691776/99614720 >> 15/04/30 00:36:49 INFO mapred.MapTask: record buffer = 262144/327680 >> 15/04/30 00:36:49 INFO mapred.LocalJobRunner: Map task executor complete. >> 15/04/30 00:36:49 WARN mapred.LocalJobRunner: job_local1121514690_0001 >> java.lang.Exception: java.lang.RuntimeException: Error in configuring >> object >> at >> org.apache.hadoop.mapred.LocalJobRunner$Job.run(LocalJobRunner.java:354) >> Caused by: java.lang.RuntimeException: Error in configuring object >> at >> org.apache.hadoop.util.ReflectionUtils.setJobConf(ReflectionUtils.java:93) >> at org.apache.hadoop.util.ReflectionUtils.setConf(ReflectionUtils.java:64) >> at >> org.apache.hadoop.util.ReflectionUtils.newInstance(ReflectionUtils.java:117) >> at org.apache.hadoop.mapred.MapTask.runOldMapper(MapTask.java:426) >> at org.apache.hadoop.mapred.MapTask.run(MapTask.java:366) >> at >> org.apache.hadoop.mapred.LocalJobRunner$Job$MapTaskRunnable.run(LocalJobRunner.java:223) >> at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) >> at java.util.concurrent.FutureTask.run(FutureTask.java:266) >> at >> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) >> at >> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) >> at java.lang.Thread.run(Thread.java:745) >> Caused by: java.lang.reflect.InvocationTargetException >> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) >> at >> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) >> at >> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) >> at java.lang.reflect.Method.invoke(Method.java:483) >> at >> org.apache.hadoop.util.ReflectionUtils.setJobConf(ReflectionUtils.java:88) >> ... 10 more >> Caused by: java.lang.NoClassDefFoundError: org/json/JSONException >> at java.lang.Class.forName0(Native Method) >> at java.lang.Class.forName(Class.java:344) >> at >> org.apache.hadoop.conf.Configuration.getClassByName(Configuration.java:810) >> at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:855) >> at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:881) >> at org.apache.hadoop.mapred.JobConf.getMapperClass(JobConf.java:968) >> at org.apache.hadoop.mapred.MapRunner.configure(MapRunner.java:34) >> ... 15 more >> Caused by: java.lang.ClassNotFoundException: org.json.JSONException >> at java.net.URLClassLoader$1.run(URLClassLoader.java:372) >> at java.net.URLClassLoader$1.run(URLClassLoader.java:361) >> at java.security.AccessController.doPrivileged(Native Method) >> at java.net.URLClassLoader.findClass(URLClassLoader.java:360) >> at java.lang.ClassLoader.loadClass(ClassLoader.java:424) >> at java.lang.ClassLoader.loadClass(ClassLoader.java:357) >> ... 22 more >> 15/04/30 00:36:50 INFO mapred.JobClient: map 0% reduce 0% >> 15/04/30 00:36:50 INFO mapred.JobClient: Job complete: >> job_local1121514690_0001 >> 15/04/30 00:36:50 INFO mapred.JobClient: Counters: 0 >> 15/04/30 00:36:50 INFO mapred.JobClient: Job Failed: NA >> Exception in thread "main" java.io.IOException: Job failed! >> at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:1357) >> at org.myorg.Wordcount.main(Wordcount.java:64) >> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) >> at >> sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) >> at >> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) >> at java.lang.reflect.Method.invoke(Method.java:483) >> at org.apache.hadoop.util.RunJar.main(RunJar.java:160) >> >> >> PS: When I modify the same code and exclude the JSON parsing i.e. find >> frequency of {‘key’:’value1’} section of the example input, all works well. >> >> >
