问题描述
最近几天我一直在试用Hadoop。我在Ubuntu 12.10上以伪分布模式运行Hadoop，并成功执行了一些标准的MapReduce作业。
接下来，我想开始尝试使用HBase。我已经安装了HBase，在shell中玩了一下。这一切都很顺利，所以我想通过一个简单的Java程序来实验HBase。我想导入以前MapReduce任务之一的输出并将其加载到HBase表中。我已经写了一个Mapper，它应该产生 HFileOutputFormat 文件，这些文件应该很容易读入HBase表。
现在，每当我运行程序（使用：hadoop jar [编译jar]），我得到一个 ClassNotFoundException 。该程序似乎无法解析 com.google.commons.primitives.Long 。当然，我认为这只是一个缺失的依赖，但JAR（谷歌的番石榴）在那里。
我尝试了很多不同的东西，但似乎找不到解决方案。
我附加了发生的Exception和最重要的类。如果有人可以帮我解决问题或给我一些建议，我会非常感激。
亲切的问候，
Pieterjan
错误
12/12/13 09:02： 54 WARN snappy.LoadSnappy：Snappy本地库未加载
12/12/13 09:03:00信息mapred.JobClient：正在运行的作业：job_201212130304_0020
12/12/13 09:03:01信息mapred .JobClient：地图0％减少0％
12/12/13 09:04:07信息mapred.JobClient：地图100％减少0％
12/12/13 09:04:51信息mapred .JobClient：任务ID：attempt_201212130304_0020_r_000000_0，状态：FAILED
错误：java.lang.ClassNotFoundException：com.google.common.primitives.Longs $ b $ java.net.URLClassLoader $ 1.run（URLClassLoader.java：在java.net.URLClassLoader中
$ 1.run（URLClassLoader.java:355）$ java.util.AccessController.doPrivileged处的
（本地方法）$ java $ .b $ java.URLClassLoader.findClass （URLClassLoader.java:354）$ java.util.ClassLoader
。 loadClass（ClassLoader.java:423）
at sun.misc.Launcher $ AppClassLoader.loadClass（Launcher.java:308）
at java.lang.ClassLoader.loadClass（ClassLoader.java:356）
at org.apache.hadoop.hbase.KeyValue $ KVComparator.compare（KeyValue.java:1554）
at org.apache.hadoop.hbase.KeyValue $ KVComparator.compare（KeyValue.java:1536）$ b $ java.util.TreeMap.compare（TreeMap.java:1188）$ b $ java.util.TreeMap.put（TreeMap.java:531）
java.util.TreeSet.add（TreeSet .java：255）
at org.apache.hadoop.hbase.mapreduce.PutSortReducer.reduce（PutSortReducer.java:63）
at org.apache.hadoop.hbase.mapreduce.PutSortReducer.reduce（PutSortReducer .java：40）
at org.apache.hadoop.mapreduce.Reducer.run（Reducer.java:176）
at org.apache.hadoop.mapred.ReduceTask.runNewReducer（ReduceTask.java:650 ）
at org.apache.hadoop.mapred.ReduceTask.run（ReduceTask.java:418）
at org.apache.hadoop.mapred.Child $ 4.run（Child.java:255）
在java.sec （用户组方法） ：1136）
at org.apache.hadoop.mapred.Child.main（Child.java:249）
JAVA
映射器：
public class TestHBaseMapper扩展Mapper< LongWritable，Text，ImmutableBytesWritable，Put> {
$ b @Override
public void map（LongWritable key，Text value，Context context）throws IOException，InterruptedException {
//制表符分隔符\t，空格分隔符：\\ \\\s +
String [] s = value.toString（）。split（\t）;
Put put = new Put（s [0] .getBytes（））;
put.add（amount.getBytes（），value.getBytes（），value.getBytes（））;
context.write（new ImmutableBytesWritable（Bytes.toBytes（s [0]）），put）;
}
工作： $ b
public class TestHBaseRun extends Configured implements Tool {
@Override
public int run（String [] args）throws Exception {
尝试{
配置配置= getConf（）;
作业hbasejob =新作业（配置）;
hbasejob.setJobName（TestHBaseJob）;
hbasejob.setJarByClass（TestHBaseRun.class）;
//指定InputFormat和路径。
hbasejob.setInputFormatClass（TextInputFormat.class）;
TextInputFormat.setInputPaths（hbasejob，new Path（/ hadoopdir / user / data / output / test /））;
//设置Mapper，MapperOutputKey和MapperOutputValue类。
hbasejob.setMapperClass（TestHBaseMapper.class）;
hbasejob.setMapOutputKeyClass（ImmutableBytesWritable.class）;
hbasejob.setMapOutputValueClass（Put.class）;
//指定OutputFormat和路径。如果路径存在，则重新初始化。
//在这种情况下，会生成可导入HBase的HFiles。
hbasejob.setOutputFormatClass（HFileOutputFormat.class）;
FileSystem fs = FileSystem.get（configuration）;
Path outputpath = new Path（/ hadoopdir / user / data / hbase / table /）;
fs.delete（outputpath，true）;
HFileOutputFormat.setOutputPath（hbasejob，outputpath）;
//检查HBase中是否存在表并在必要时创建它。
HBaseUtil util = new HBaseUtil（configuration）;
if（！util.exists（test））{
util.createTable（test，new String [] {amount}）;
}
//读取现有的（或新创建的）表格。
配置hbaseconfiguration = HBaseConfiguration.create（configuration）;
HTable table = new HTable（hbaseconfiguration，test）;
//将HFiles写入磁盘。自动配置分区器和减速器。
HFileOutputFormat.configureIncrementalLoad（hbasejob，table）;
布尔成功= hbasejob.waitForCompletion（true）;
//将生成的文件加载到表中。
LoadIncrementalHFiles加载器;
loader = new LoadIncrementalHFiles（hbaseconfiguration）;
loader.doBulkLoad（outputpath，table）;
返回成功？ 0：1;
} catch（Exception ex）{
System.out.println（Error：+ ex.getMessage（））;
}
返回1;
ClassNotFoundException ，这意味着找不到包含com.google.common.primitives.Longs的所需.jar。
有几种方法可以解决此问题： / p> 将所需.jar的路径添加到 export HADOOP_CLASSPATH =< jar_files>：$ HADOOP_CLASSPATH 在您的根项目文件夹中创建一个文件夹 / lib 。将您的.jar复制到该文件夹中。为您的项目创建一个包（.jar）。结果将是一个包含所有包含在 / lib 中的所有jar的胖罐子。 The last few days I've been experimenting with Hadoop. I'm running Hadoop in pseudo-distributed mode on Ubuntu 12.10 and successfully executed some standard MapReduce jobs. Next I wanted to start experimenting with HBase. I've installed HBase, played a bit in the shell. That all went fine so I wanted to experiment with HBase through a simple Java program. I wanted to import the output of one of the previous MapReduce jobs and load it into an HBase table. I've wrote a Mapper that should produce Now, whenever I run the program (using: hadoop jar [compiled jar]) I get a I've tried a lot of different things but can't seem to find a solution. I attached the Exception that occurs and the most important classes. I would be truly appreciated if someone could help me out or give me some advice on where to look. Kind regards,Pieterjan ERROR JAVA Job: ClassNotFoundException, it means that the required .jar that contains com.google.common.primitives.Longs cannot be found. There are several ways to solve this issue: Add the path to the required .jar to export HADOOP_CLASSPATH="<jar_files>:$HADOOP_CLASSPATH" Create a folder /lib in your root project folder. Copy your .jar into that folder. Create a package (.jar) for your project. The result will be a fat jar contained all the jars included in /lib. 这篇关于将MapReduce输出数据加载到HBase中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！
HADOOP_CLASSPATH 。打开 /etc/hbase/hbase-env.sh 并添加：
HFileOutputFormat files that should easily read into a HBase table.ClassNotFoundException. The program seems unable to resolve com.google.commons.primitives.Long. Of course, I thought it was just a dependency missing but the JAR (Google's Guava) is there. 12/12/13 09:02:54 WARN snappy.LoadSnappy: Snappy native library not loaded
12/12/13 09:03:00 INFO mapred.JobClient: Running job: job_201212130304_0020
12/12/13 09:03:01 INFO mapred.JobClient: map 0% reduce 0%
12/12/13 09:04:07 INFO mapred.JobClient: map 100% reduce 0%
12/12/13 09:04:51 INFO mapred.JobClient: Task Id : attempt_201212130304_0020_r_000000_0,Status : FAILED
Error: java.lang.ClassNotFoundException: com.google.common.primitives.Longs
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
at org.apache.hadoop.hbase.KeyValue$KVComparator.compare(KeyValue.java:1554)
at org.apache.hadoop.hbase.KeyValue$KVComparator.compare(KeyValue.java:1536)
at java.util.TreeMap.compare(TreeMap.java:1188)
at java.util.TreeMap.put(TreeMap.java:531)
at java.util.TreeSet.add(TreeSet.java:255)
at org.apache.hadoop.hbase.mapreduce.PutSortReducer.reduce(PutSortReducer.java:63)
at org.apache.hadoop.hbase.mapreduce.PutSortReducer.reduce(PutSortReducer.java:40)
at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:176)
at org.apache.hadoop.mapred.ReduceTask.runNewReducer(ReduceTask.java:650)
at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:418)
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:415)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1136)
at org.apache.hadoop.mapred.Child.main(Child.java:249)
Mapper:public class TestHBaseMapper extends Mapper<LongWritable, Text, ImmutableBytesWritable, Put> {
@Override
public void map(LongWritable key, Text value, Context context) throws IOException, InterruptedException {
//Tab delimiter \t, white space delimiter: \\s+
String[] s = value.toString().split("\t");
Put put = new Put(s[0].getBytes());
put.add("amount".getBytes(), "value".getBytes(), value.getBytes());
context.write(new ImmutableBytesWritable(Bytes.toBytes(s[0])), put);
}
public class TestHBaseRun extends Configured implements Tool {
@Override
public int run(String[] args) throws Exception {
try {
Configuration configuration = getConf();
Job hbasejob = new Job(configuration);
hbasejob.setJobName("TestHBaseJob");
hbasejob.setJarByClass(TestHBaseRun.class);
//Specifies the InputFormat and the path.
hbasejob.setInputFormatClass(TextInputFormat.class);
TextInputFormat.setInputPaths(hbasejob, new Path("/hadoopdir/user/data/output/test/"));
//Set Mapper, MapperOutputKey and MapperOutputValue classes.
hbasejob.setMapperClass(TestHBaseMapper.class);
hbasejob.setMapOutputKeyClass(ImmutableBytesWritable.class);
hbasejob.setMapOutputValueClass(Put.class);
//Specifies the OutputFormat and the path. If The path exists it's reinitialized.
//In this case HFiles, that can be imported into HBase, are produced.
hbasejob.setOutputFormatClass(HFileOutputFormat.class);
FileSystem fs = FileSystem.get(configuration);
Path outputpath = new Path("/hadoopdir/user/data/hbase/table/");
fs.delete(outputpath, true);
HFileOutputFormat.setOutputPath(hbasejob, outputpath);
//Check if table exists in HBase and creates it if necessary.
HBaseUtil util = new HBaseUtil(configuration);
if (!util.exists("test")) {
util.createTable("test", new String[]{"amount"});
}
//Reads the existing (or thus newly created) table.
Configuration hbaseconfiguration = HBaseConfiguration.create(configuration);
HTable table = new HTable(hbaseconfiguration, "test");
//Write HFiles to disk. Autoconfigures partitioner and reducer.
HFileOutputFormat.configureIncrementalLoad(hbasejob, table);
boolean success = hbasejob.waitForCompletion(true);
//Load generated files into table.
LoadIncrementalHFiles loader;
loader = new LoadIncrementalHFiles(hbaseconfiguration);
loader.doBulkLoad(outputpath, table);
return success ? 0 : 1;
} catch (Exception ex) {
System.out.println("Error: " + ex.getMessage());
}
return 1;
}
HADOOP_CLASSPATH. To do so open /etc/hbase/hbase-env.sh and add: